Yoshiki Noguchi

Cooperative clinical trial of photodynamic therapy with photofrin II and excimer dye laser for early gastric cancer

Photodynamic therapy (PDT) is a recently developed endoscopic method for treating malignant tumors. For obtaining more photodynamic action with less thermal effect, we employed as the excitation light source for PDT an excimer dye laser, which is a pulsed laser with extremely high peak power, instead of an argon dye laser, which is a continuous wave laser and has been used conventionally.

Effects of Betazole Hydrochloride and Cyclic AMP on the Pepsinogen Secretion by Rabbit Gastric Mucosa in Organ Culture

The effects of betazole hydrochloride, dibutyryl cyclic AMP (DB-cyclic AMP) and betazole hydrochloride plus aminophylline on pepsinogen secretion by rabbit gastric mucosa were studied in organ culture. Betazole hydrochloride alone did not stimulate pepsinogen secretion at the concentrations of 10(-8), 10(-6), 10(-5) and 10(-4) M. However, 10(-3) M DB-cyclic AMP produced a significant stimulation of pepsinogen secretion into the culture medium when compared with the control. In the presence of 3 x 10(-3) M aminophylline, betazole hydrochloride in the concentration of 10(-5) and 10(-4) M stimulated pepsinogen secretion into the culture medium, and the magnitude of this increase was 2.0- and 2.8-fold, respectively, compared with the control. Aminophylline alone could not change pepsinogen secretion into the culture medium. These results suggested that the pepsinogen secretion, stimulated by betazole hydrochloride, was mediated by cyclic AMP in the chief cells.

Effects of cyclic nucleotides, betazole hydrochloride and acetylcholine on pepsinogen secretion from isolated rabbit gastric mucosa

SummaryThe effects of dibutyryl cyclicAMP (db-cAMP), dibutyryl cyclicGMP (db-cGMP), betazole hydrochloride (betazole) and acetylcholine (ach.) on pepsinogen secretion from isolated rabbit gastric mucosa were studied using an organ culture system. The 10-3 M db-cAMP, but not db-cGMP of any concentration, produced a significant enhancement of pepsinogen secretion into the culture medium. In the presence of aminophylline (phosphodiesterase inhibitor), betazole stimulated pepsinogen secretion at concentrations of 10-8, 10-6 and 10-4 M. The 10-4 M betazole stimulated pepsinogen secretion most strongly (208% of control) and 10-6 M betazole induced submaximal secretion (137% of control). Ach. stimulated pepsinogen secretion at 10-8, 10-6, 10-4 and 10-2 M. The peak secretion occurred at 10-4 M ach. (303% of control). Betazole (with aminophylline) against a background of 10-6 M ach. (submaximal stimulation dose), produced an intense stimulation of pepsinogen secretion at the concentrations of 10-8, 10-6 and 10-4 M, and the secretion rate expressed as percent of control were 277, 350 and 329%, respectively. These responses were not considered the additive action by betazole and ach. but the potential interaction between the two agents in pepsinogen secretion. From these findings, we conclude that betazole-ach. interdependency exists in in vitro pepsinogen secretion.