Electrical control of elasticity was performed in piezoelectric polymer films by connecting an electric circuit parallel to the sample electrodes. A polyvinylidene fluoride film and a vinylidene fluoride tetrafluoroethylene copolymer (73/27) film were used. Electrical circuits acting as a variable negative capacitor or a variable inductor were constructed using operational amplifiers. Theoretically, when the value of the external negative capacitance is increased, the observed elastic constant increases from that at an open circuit to positive infinity at around the value of the sample, turns to negative infinity, and then increases through zero to that at a short circuit. If the inductance of the external circuit is changed around the electrical resonant frequency, the elastic constant exhibits resonance and antiresonance against frequency. Experimental observations of the characteristics of the dynamic elastic constant agreed well with these theoretical predictions. By coupling the negative capacitance, the elastic constant changed between 0.5 and 2 times the original value, and the elastic loss increased to tan δ=0.7.

Background : Various types of classification of gastritis have been proposed, but no plausible classification has been available until now. The Research Society for Gastritis performed a pilot study to establish an endoscopic classification, taking into consideration the following: (i) ease of use; (ii) permitting everyone the common image; and (iii) presence of histopathological evidence. Methods : One hundred and fifty-five patients were enrolled and underwent gastroscopy. Eight basic endoscopic and histological types of gastritis (superficial, hemorrhagic, erosive, verrucous, atrophic, metaplastic, hyperplastic and special types) were defined. Gastritis was endoscopically diagnosed according to the definition of the endoscopic types of gastritis. Four or more biopsy specimens were obtained from the lesser and the greater curvatures of the antrum and the corpus of each patient, and the histological findings of gastritis and Helicobacter pylori infection were assessed. The histological diagnosis of gastritis was made according to the definition of histology types of gastritis. The endoscopic and the histological diagnoses were then compared in a blinded fashion. Results : Endoscopic diagnosis was 62% as sensitive as histological diagnosis for erosive gastritis, 67% for verrucous gastritis and 84% for atrophic gastritis in the antrum. In superficial gastritis, sensitivity was approximately 25% in the corpus, but only 8% in the antrum. Metaplastic and hyperplastic gastritis were correctly diagnosed only in severe cases. Conclusion : Five basic types of gastritis (superficial, erosive, verrucous, atrophic and special types) should be employed for the new endoscopic gastritis classification. Metaplastic and hyperplastic gastritis are considered to be subtypes of atrophic gastritis and they should be excluded from the basic endoscopic classification. A new definition of gastritis in the antrum accompanied by redness still remains to be investigated.

Stomach-partitioning gastrojejunostomy achieved an improved quality of life and a better prognosis for patients, and it is the preferred bypass procedure for unresectable gastric carcinoma.

Three new oleanolic acid glycosides, tarasaponins I-III, were isolated as their methyl esters from the root bark of Aralia elata together with four known glycosides, the methyl esters of chikusetsusaponins IVa, IV, 28-desglucosyl-chikusetsusaponin IV and pseudoginsenoside RT1. Tarasaponins I-III were characterized as oleanolic acid 3-O-[beta-D-glucopyranosyl(1-->3)][alpha-L-arabinofuranosyl(1-->4)[- beta-D-glucuronopyranoside, oleanolic acid 3-O-[beta-D-xylopyranosyl(1-->2)][beta-D-galactopyranosyl(1-->3)]-beta- D-glucuronopyranoside and beta-D-glucopyranosyl oleanolate 3-O-beta-D-galactopyranosyl(1-->3)-beta-D-glucuronopyranoside, respectively.

Background. Gastric mucosal blood flow, secretion of mucin, and renewal of the gastric mucosal cells are considered to be defensive factors against gastric mucosal injuries. These factors are regulated by the nervous system and neuropeptides. Gastrectomy may affect this regulation and induce gastric mucosal changes, such as atrophic gastritis and carcinoma. The effects of denervation of the gastric mucosa on tumorigenesis of the remnant stomach were investigated. Methods. Using male Wistar rats, four groups of Bill‐roth I (B‐I) gastrectomy, Billroth II (B‐II) gastrectomy, and those with denervation were conducted. Subdiaphragmatic truncal vagotomy was performed in the denervated group. Thirty weeks after the operations, histologic examination and periodic acid‐Schiff—Alcian blue (PAS‐AB) staining of the gastric mucosa, analysis of cell kinetics of the gastric mucosa by immunohistochemistry of proliferating cell nuclear antigen, and measurement of intragastric pH, intragastric bile acid concentration, and serum gastrin levels were performed. No carcinogenic agents were given. Results. The B‐I group showed no remarkable gastric mucosal changes, but B‐I with denervation showed a significant increase in the development of tumor (67%) and carcinoma (42%). In the B‐II groups, the denervation induced a significant increase in tumorigenesis, from 22% to 58%. Analysis of cell kinetics revealed a significant increase of labeling index in those groups that developed tumors. PAS‐AB staining showed a decrease of PAS positive mucin but an increase of acidic mucin‐producing cells in the denervated groups, suggesting an increase in the number of immature cells that are more susceptible to atrophic gastritis and carcinoma. There was no close relationship between tumorigenesis and intragastric pH, intragastric bile acid concentration, or serum gastrin levels. Conclusions. After gastrectomy, not only duodenogastric reflux, but also the denervation of the gastric mucosa play an important role in the etiology of gastric remnant cancer. Cancer 1995;75:1490‐6.