Takeshi Oinuma

Evaluation of a novel high-resolution magnifying videoendoscope that is capable of photodynamic diagnosis and therapy for gastric cancer

OBJECTIVE To evaluate the usefulness of a novel high-resolution magnifying videoendoscope called the XG-0001 (Fujifilm, Tokyo, Japan) that is capable of PDD and PDT in experimental and clinical situations. MATERIALS AND METHODS The fluorescences of three photosensitizers (i.e., porfimer sodium (Photofrin), protoporphyrin IX and talaporfin sodium (Laserphyrin)) were studied experimentally via excitation with a purple diode laser (VDL, wavelength 405nm). Five consecutive patients with superficial early gastric cancer not indicated for surgery or other curative endoscopic treatment due to complicated serious diseases were enrolled in this study. After close endoscopic examinations, 2mg/kg of Photofrin were intravenously injected into the patients for PDT, and 5-aminolevulinic acid (ALA; 15-20mg/kg) was orally taken for PDD. PDD using VDL and PDT using an excimer-dye laser (630nm, 4mJ, 60Hz) were performed with the XG-0001. RESULTS Photofrin and Laserphyrin had experimentally the lowest and highest fluorescence intensities, respectively. The five patients comprised four men and one woman with a mean age 75.2 year and an age range of 56-83 years. Two additional cancerous lesions were newly detected by magnifying pharmacoendoscopy. In each patient, PDD was successfully performed. PDT could also safely performed and CR was obtained in 71.4% (5/7) of the cancerous lesions in five patients, and no serious complications were encountered. CONCLUSION The XG-0001, which is based on a simultaneous videoendoscopy method that uses an RGB color chip CCD, proved extremely useful in routine use and also in PDD and PDT for gastric cancer.

3558 Argon plasma coagulation for eradication of esophageal varices after treatment with endoscopic variceal banding ligation or sclerotherapy.

Background: Endoscopic variceal banding ligation (EVL) and sclerotherapy (EVS) have been used to prevent variceal hemorrhage. However, the rate of recurrence of esophageal varices after EVL or EVS is considerably high. Argon plasma coagulation (APC) is a new modality of electrosurgery to apply high frequency electric current into tissue to cause defined thermal effects. This study was conducted to determine whether APC is beneficial for eradication of residual esophageal varices after EVL or EIS. Methods: Cirrhotic patients with endoscopically assessed high-risk esophageal varices but no history of bleeding underwent EVL or EIS to reduce the risk of hemorrhage. When the size of varices was reduced 1 week later, the entire esophageal mucosae 4-5 cm proximal to the esophagogastric junction was coagulated with one session of APC in a total of 15 patients.APC was performed with the use of argon source APC300 and high frequency generator ICC 200 (ERBE, Germany). Follow-up endoscopy was performed 7 days and 1 month after the initial procedure and thereafter every 3 months, to check for recurrent/residual esophageal varices and its complications. Results: Ten to 14 days after APC, ulcerations with white coating were noted in all cases, whereas varices were completely eradicated. One month after APC, while the varices remained eradicated, coagulated esophageal mucosae became whitish and the ulcerations were nearly completely healed. During the course, no patients complained of dysphagia or retrosternal pain. Furthermore, neither development of gastric varices nor aggravation of portal hypertensive gastropathy was observed endoscopically. No serious complication such as bleeding necessitating endoscopic therapy and perforation or stricture of the esophagus was encountered. Over a maximum follow-up period of 5 months, neither recurrence of nor hemorrhage from esophageal varices was observed. Conclusions: APC ablation of residual esophageal varices in patients who have undergone prior EVL or EIS is safe and may be a novel approach to eradicate esophageal varices. It requires a long term follow-up of the eradicated varices to further evaluate its efficacy.

Role of iron and lipid peroxidation in mediating peroxynitrite-induced toxicity to cultured gastric mucosal cells

that endoscopically negative patients with GER-related symptoms may have enhanced protective mechanisms. Aims: 1. To assess bicarbonate, non-bicarbonate, protein, transforming growth factor ct (TGFtx) and prostaglandin E 2 (PGE2) in salivary secretion in patients with endoscopically negative [E(-)] GERD. 2. To compare the obtained results with corresponding values in asymptomatic controls (C) and patients with RE~ Subjects & Methods: The study was conducted in 30 patients with RE (12F & 18M, mean age of 49), in 39 asymptomatic volunteers (16F & 23M, mean age of 40), and in 10 patients with E(-) GERD (SF & 5M, mean age of 40). Salivary secretions were collected under basal conditions, daring mastication, and during intraesophageal mechanical and chemical stimulation, mimicking the GER scenario, using an esophageal perfusion catheter. Salivary bicarbonate and non-bicarbonate were measured using Titra-Lab (Radiometer America, IL). Salivary protein was quantitated using Lowry method, whereas TGFot, and PGE z by RIA (Amersham, IL and Biomed. Technol. Inc. MA). Statistical analysis was implemented by E-Stat (Jandel Sci. CA) software. Results: Salivary bicarbonate in patients with E(-) GERD was significantly higher than in C and in RE during intraesophageal chemical stimulation (P < 0.05). Salivary protein was significantly higher in GERD E(-) than in and RE during intraesophageai mechanical and chemical stimulation (P < 0.05). Salivary TGFot output in GERD E(-) was significantly higher than in RE (P < 0.05) but not controls during intraesophageal mechanical stimulation. Salivary PGE z output, on the other hand, in GERD E(-) was significantly higher than in C (P < 0.05) but not RE during intraesophageal chemical stimulation. Conclusion: . A strong salivary secretory response to intraesophageal mechanical and chemical stimuli in patients with GERD E(-) in terms of bicarbonate, protein, TGFa, and PGE z seem to mediate resistance to the development of endoscopic mucosal changes by GER. ° This could explain t he lack of endoscopic esophagitis in the majority of GERD patients and could be a therapeutic target in future treatment strategies.

Polaprezinc protects gastric mucosal cells from noxious agents through anti-oxidant properties in vitro

BACKGROUND Polaprezinc has been shown to exert an anti-oxidant property in a tube experiment, protect gastric mucosa from experimental ulcerations in vivo, and accelerate the healing of gastric ulcer in humans. AIM To examine a possible protective effect of polaprezinc on oxidant-mediated injury in primary monolayer cultures of rat gastric fundic mucosa. METHODS Cytotoxicity was quantified by measuring 51Cr release. Whether or not polaprezinc exerts an antioxidant property was investigated by determining the effect of this agent on hydrogen peroxide (H2O2)-induced injury. The effects of polaprezinc on superoxide (O2-. ) generation as well as on ethanol (EtOH)-induced injury were also examined. Generation of O2-. was assessed by the reduction in cytochrome c. RESULTS H2O2 caused a time- and dose-dependent increase in 51Cr release. The dose-response curve of 51Cr release by H2O2 shifted to the right in the presence of polaprezinc. Polaprezinc, at submillimolar concentrations, prevented H2O2-induced 51Cr release. EtOH also caused a dose-dependent increase in 51Cr release, which was prevented by the addition of polaprezinc. The incubation of cells with EtOH caused an increase in cytochrome c reduction, as the concentrations of EtOH increased. Polaprezinc inhibited EtOH-induced cytochrome c reduction. Protection by polaprezinc was microscopically associated with the prevention of monolayer disruption. CONCLUSIONS Polaprezinc is antioxidative and directly protects gastric mucosal cells from noxious agents through its antioxidant properties in vitro. This finding may provide the theoretical basis for the usage of an antiulcer drug with antioxidant properties for the treatment of gastric inflammation, such as that induced by ethanol.