Hiroaki Niwamoto

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In order to test the hypothesis that esophageal achalasia may be due to neurotropic viral damage to the esophageal myenteric plexus, esophageal tissue with or without achalasia was analyzed by polymerase chain reaction for the presence of human herpes virus DNA or measles virus RNA. The DNA and RNA were extracted from the esophageal muscle of 12 patients(More)
Hepatitis B virus is associated with human hepatocellular carcinoma. We performed polymerase chain reaction for the X, C, S, and preS2/S regions of the viral genome in 23 hepatitis B surface antigen-negative hepatocellular carcinomas and adjacent liver. Hepatitis B viral genomes were detected in 17 of 23 tumors and adjacent tissues (73.9%). Among recognized(More)
The disturbance of defecation in the patient with Hirschsprung's disease and the pathophysiology of constipation in the constipated patient with simple megarectum were investigated. In Hirschsprung's disease, an existence of aganglionosis and the sphincter achalasia are two main factors which cause clinical symptoms such as chronic constipation and(More)
We encountered three cases of chronic functional colonic obstruction caused by intramural ganglion cell death. Morphologic and pharmacological studies were performed using resected specimens. The patients included a 59-year-old man, a 72-year-old woman, and a 28-year-old man. Barium enema studies revealed segmental stenosis in their left colon. A mecholyl(More)
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