Current status of diagnostic imaging in dental university hospitals in Japan

The diagnostic imaging examinations in all 29 dental university hospitals in Japan were analyzed during a 1-year period from April 1999 to March 2000. The total number of patients examined was 790859, which corresponded to 27271 patients per hospital on average, with a range from 7872 to 62904. Relative to the total number of patients, intraoral radiography was found to have been most frequently performed, 59% on average, with a range from 40% to 80%, depending on the hospital. Extraoral radiography, mostly panoramic radiography, was 36% on average with the range from 18% to 56%.A significant inverse correlation was observed between the percentages of intraoral and extraoral radiography, relative to the total number of all types of imaging examinations. Computed tomography (CT) examinations were performed with their own apparatuses in 27 hospitals with a frequency of 2.9% of patients in all imaging examinations on average and 9.1% at maximum. The scanning parameter of milliampere seconds (mAs) for individual types of routinely performed CT examinations varied widely, and thus the patient dose can be expected to be considerably reduced, without reducing the amount of diagnostic information to be obtained. Other imaging examinations performed were magnetic resonance imaging in 11 hospitals, X-ray fluoroscopy in 8 hospitals, ultrasonography in 20, nuclear medicine in 5, and bone densitometry in 1 hospital.A report from the Radiation Protection Committee (Chairperson, T. Sasaki), Japanese Society for Oral and Maxillofacial Radiology. A portion of this study was presented at the 4th ACOMFR, June 16, 2002, Kaohsiung, Taiwan.     

Acotiamide hydrochloride (Z-338), a novel prokinetic agent, restores delayed gastric emptying and feeding inhibition induced by restraint stress in rats

Abstract  Acotiamide hydrochloride (Z-338) is a member of new class prokinetic agents currently being developed for the treatment of functional dyspepsia (FD). DNA microarray analysis showed that acotiamide altered the expressions of stress-related genes such as γ -aminobutyric acid (GABA) receptors, GABA transporters and neuromedin U (NmU) in the medulla oblongata or hypothalamus after administration of acotiamide. Therefore, effects of acotiamide on stress-related symptoms, delayed gastric emptying and feeding inhibition, in rats were examined. Acotiamide significantly improved both delayed gastric emptying and feeding inhibition in restraint stress-induced model, but did not affect both basal gastric emptying and feeding in intact rats, indicating that acotiamide exerted effects only on gastric emptying and feeding impaired by the stress. On the other hand, mosapride showed significant acceleration of gastric emptying in intact and restraint stress-induced model, and itopride showed no effect on restraint stress-induced delayed gastric emptying. In addition, gene expression of NmU increased by restraint stress was suppressed by administration of acotiamide, while acotiamide had no effect on delayed gastric emptying induced by an intracerebroventricular administration of NmU, suggesting that the suppressive effect of acotiamide on gene expression of NmU might be important to restore delayed gastric emptying or feeding inhibition induced by restraint stress. These findings suggest that acotiamide might play an important role in regulation of stress response. As stress is considered to be a major contributing factor in the development of FD, the observed effects may be relevant for symptom improvement in FD.     

Contraction induced by glicentin on smooth muscle cells from the human colon is abolished by exendin (9–39)

Glicentin and glucagon-like peptide-1 (7-36) amide (GLP-1) are gut hormones released during digestion. Glicentin and GLP-1 slow down gastric emptying and glicentin can switch off the duodenojejunal fed motor pattern. The effect of glicentin on the motor activity of colon has never been reported in humans. Our aim was to determine if circular smooth muscle cells (SMC) from the human colon are target cells for glicentin or GLP-1, and if their motility is dependent upon these digestive hormones. METHODS: Twenty-two resections were performed on patients operated for colon adenocarcinoma. The SMC were isolated from colonic circular muscle layer and cell contraction was assessed. RESULTS: Glicentin caused a dose-related contraction of SMC, when GLP-1 determined a contraction of weak amplitude. Exendin-(9-39), described as a GLP-1 receptor antagonist, inhibited contraction due to glicentin or GLP-1. In contrast, on antral SMC from rabbit, GLP-1 exerts neither relaxation nor contraction; however, exendin-(9-39) dose dependently reduced the contractile activity of glicentin [glicentin EC(50) = 5 pM, exendin-(9-39) pA(2) = -9.36]. CONCLUSIONS: The circular muscle from the human colon is a target tissue for glicentin and GLP-1. Whereas glicentin is a long-life digestive hormone which would contribute to segmental contraction, the biological activity of GLP-1 remains unknown on this tissue. On the digestive smooth muscle, exendin-(9-39) behaved as an antagonist for two members of the glucagon-receptor family, GLP-1 and glicentin.