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Biomedical subjects

Shinsuke Matsuda

Publications and source records attributed to Shinsuke Matsuda.

4 recordsLinked to original sources
PubMed2007

Mouthguards: difference in longitudinal dimensional stability between single- and double-laminated fabrication techniques.

Though the use of mouthguards (MGs) has increased with the increase in sporting activities, little is known about the influence of their fabrication methods on longitudinal dimensional stability. The objective of this study was to compare the difference in the longitudinal dimensional stability between single and laminated MGs. Single-layer MGs were made from a 4.0 mm thick ethylene vinyl acetate (EVA) sheet and laminated MGs were made from two 2.0 mm thick sheets of EVA. MGs were kept in a 37 degrees C water bath for 60 h, equivalent to the time period of 3-months inter-oral use. MG deformation was analyzed by measuring designated points on the MG border using a profile projector (J-12, Nikon Inc., Tokyo, Japan) before and after the water immersion. A finite-element model was also created to examine the time course of stress accumulation during the sheet forming process using Finite Element software. Longitudinal deformation was smaller in the laminated MGs than in the single-layer MGs in the anterior area (P < 0.05). Finite element method (FEM) analysis also showed the largest stress accumulation in the anterior incisal area where deformations were mainly observed. Laminated double layer MGs have advantages over single-layer MGs in terms of longitudinal stability due to lower stress accumulation during the fabrication process.

Equipment Design↗
PubMed2002

Inhibitory effect of loxiglumide (CR 1505), a cholecystokinin receptor antagonist, on N-nitrosobis(2-oxopropyl) amine-induced biliary carcinogenesis in Syrian hamsters.

We evaluated the cholecystokinin (CCK) receptor antagonist loxiglumide (CR1505) for a possible inhibitory effect on biliary carcinogenesis in a hamster model. Experimental group I underwent cholecystoduodenostomy and ligation of the distal end of the common bile duct, after which the animals were injected with N-nitrosobis(2-oxopropyl)amine (BOP) alone. Group II, after the same surgical procedure as in group I, were given injections of BOP and then given loxiglumide in their diet. The sham-operated group underwent simple laparotomy and then were given injections of BOP. Loxiglumide significantly inhibited BOP carcinogenicity in the gallbladder and extrahepatic bile duct but not in the intrahepatic bile ducts or pancreas. Autoradiography showed that loxiglumide significantly suppressed (125)I-Bolton-Hanter (BH)-CCK-8 binding to CCK receptors in the gallbladder and extrahepatic bile duct but not in the liver or pancreas, and CCK binding to its receptors was observed in an area identified as cancer tissue. CCK receptor antagonists have an inhibitory effect on BOP carcinogenesis in the extrahepatic biliary tract, including the gallbladder and extrahepatic bile duct, of Syrian hamsters. The difference in the inhibitory effect of loxiglumide on biliary carcinogenesis in hamsters according to site may be due to differences in CCK receptors or the affinity of loxiglumide for such biliary tract organs. A difference between carcinogenesis in the intrahepatic bile ducts and extrahepatic biliary tract may be another reason.

Adenocarcinoma, Papillary↗
PubMed2002

Somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease.

We report a case of somatostatinoma of the papilla of Vater with multiple gastrointestinal stromal tumors in a patient with von Recklinghausen's disease (VRD). A 64-year-old woman who had had recurrent attacks of acute pancreatitis and cholangitis was found, on gastroduodenal endoscopy, to have a tumor of the papilla of Vater and multiple submucosal tumors of the stomach and duodenum. Numerous submucosal tumors were observed in the stomach, duodenum, and jejunum, and total excision of the papilla of Vater and resection of the duodenal and jejunal submucosal tumors was performed. The tumor of the papilla of Vater showed the histologic appearance of a dense proliferation of tumor cells in acinar form, from the duodenal mucosa to the muscle layer, and psammoma bodies were revealed within the tumor. Immunohistologically, the tumor cells were intensely positive for somatostatin. The submucosal tumors of the duodenum and jejunum were negative for smooth muscle actin, s-100, and neuron-specific enolase (NSE), and positive for CD34 and c-kit, and they were diagnosed as gastrointestinal stromal tumors (GISTs) according to the strict definition. The only 25 cases of papilla of Vater somatostatinoma associated with VRD to have been reported in the English-language literature since 1982 are reviewed, as well as our own case.

Ampulla of Vater↗