Minoru Kawaguchi

Bacteria closely resembling Helicobacter pylori detected immunohistologically and genetically in resected gallbladder mucosa.

A microorganism with close immunohistological and genetic resemblance toHelicobacter pylori was found in the resected gallbladder mucosa of a 41-year-old woman. The woman was admitted to hospital complaining of fever and right hypochondrial pain. Cholecystectomy was carried out under the diagnosis of gallstones and cholecystitis. A microorganism resemblingH. pylori (stained with H&E, Giemsa, and Wartin-Starry) was detected incidentally on pathological examination. The microorganism was also positive for immunohistochemical staining. An amplification reaction was seen on genetic examination by the polymerase chain reaction (PCR) method (urease β-genes). Our findings suggest thatH. pylori may be present in tissues other than gastric mucosa.

Evaluation of photodynamic therapy in gastric cancer

Twenty-eight patients with gastric cancer were treated by photodynamic therapy. Haematoporphyrin derivative was used as a photosensitizer and an argon dye laser as a light source. Histologically, all tumours were adenocarcinomas. On the basis of endoscopy, 17 cases were categorized as early-stage cancer and were classified as type IIc (10 lesions), Ha (three lesions), combined type IIc and type III (three lesions) and type I (two lesions). In 11 patients with advanced-stage cancer, endoscopy showed one case of Borrmann I, three of Borrmann II, six of Borrmann III and a single case of Borrmann IV. In the 17 patients with early-stage cancers (18 lesions), complete remission was obtained in 10 patients (11 lesions). Of 13 resected cancers complete remission was confirmed in six lesions on the basis of detailed histological examination of resected specimens. In the advanced stage tumours all 11 patients showed incomplete remissions. It is considered that an incomplete response in the early-stage cancers is due to insufficient light dosage because of the wide area of tumour, because the site of the lesion is anatomically difficult to photoradiate and because the invasion extends to the muscular layer and serosa.

Effect of activin on cell growth in primary cultures of guinea pig gastric epithelial cells

Background: The effect of activin on differentiated cells is known to be different from that on undifferentiated cells. Cultured gastric epithelial cells in complete serum‐free conditions grew into matured mucous cells after treatment with epidermal growth factor (EGF).

Incidence of Gastric Metaplasia and Helicobacter pylori Infection in Duodenal Bulb - With Specific Reference to Patients With Duodenal Ulcers.

We determined the incidence of gastric metaplasia in the duodenal bulb of duodenal ulcer patients and the Helicobacter pylori (H. pylori) infection rate at sites with gastric metaplasia. Biopsy of the duodenal bulb showed the presence of gastric metaplasia in 61 of 86 patients (71%) overall and in 18 of 47 patients (38.3%) who had gastrectomy at an early gastric cancer. The histological diagnosis of H. pylori infection showed good agreement (83.3%) with the result of the rapid urease test, indicating that H. pylori occurs in regions with gastric metaplasia. This finding suggests that H. pylori infects gastric metaplasia in the duodenal bulb, causing mucosal injury, which is then transformed into duodenal ulcers. The exact mechanism by which gastric metaplasia is caused is unknown, but it is believed to occur in the transitional zone in the duodenal mucosa.

New Gastric Lesion in the Cardia Induced by Proton Pump Inhibitor Treatment

BACKGROUND: Incomplete resection of adenomatous polyps likely contributes to interval colorectal carcinomas following a complete colonoscopy. However, data on adequacy of adenoma resection is lacking. OBJECTIVE: Examine the rate of incompletely resected adenomatous polyps. METHODS: We prospectively enrolled individuals presenting for colonoscopy at two medical centers and studied those found with at least one non-pedunculated polyp between 5 and 20mm. After obtaining a standardized measure of polyp size, polyps were removed by experienced Attending Gastroenterologists using snare polypectomy with cautery. Once polyp removal was considered complete, either two or four biopsies were obtained from the resection margin for 5-9mm polyps and 10-20mm, respectively. Adenomatous polyps were considered incompletely resected if any of the marginal biopsies contained adenomatous tissue. The main outcome measure was the rate of incompletely resected adenomas overall and by size. We performed regression analysis to examine the association between incomplete resection and size, anatomic location, and location with respect to colonic folds. RESULTS: 417 study polyps were removed from 271 patients (83.4% men, mean age 63.4 years) by 11 Gastroenterologists. 345 of these polyps were adenomatous (n=344) or contained cancer (n=1), and 64 polyps were hyperplastic with the remaining being juvenile, inflammatory, or mucosal prolapse. The overall incomplete adenoma resection rate was 10.1% (95%CI 6.9-13.3%). Incomplete resection was significantly more common for large adenomas (17.4%, 95%CI 10.2-24.7%) relative to small adenomas (6.8%, 95%CI 3.5%-10.0%; p=0.002). In adjusted regression analysis, large adenomas were 2.5 times more likely than small adenomas to be incompletely removed (OR=2.5, CI 1.15.3). Incomplete resection was common for serrated adenomas with an overall incomplete resection rate of 31.5% (95% CI 16.6-44.9%) and a 50.0% (95%CI 27.3-72.7) rate for large serrated adenomas. Distal or proximal location in the colon or the location of the polyp on or behind a fold was not associated with incomplete resection. CONCLUSION: Even under study conditions experienced Gastroenterologists incompletely resected a high proportion of adenomas. Assuming that microscopic residual adenomatous tissue is clinically important, additional efforts need to be implemented to ensure complete resection, especially of larger lesions.

Primary cancer of the small intestine and mutational analysis of the K-ras and p53 genes

Abstract: A 69-year-old woman was admitted to Hokuso Shiroi Hospital because of recurrent pain in the lower right side of the abdomen. Small-intestinal cancer was strongly suspected after fluoroscopy of the small intestine. Laparotomy showed advanced cancer of the ileum, of complete annular constrictive type, 9.5 × 5 cm in size. Histologically it was moderately differentiated tubular adenocarcinoma. Neither visceral nor nodal metastases were found, and the patient has been well for the 20 months since surgery. The strong resemblance between the epidemiological characteristics of small-intestinal cancers and colorectal cancers prompted us to investigate the carcinogenetic mechanisms at the molecular level. A point mutation at codon 12 of the K-ras gene was found, while no alterations were noted in the p53 gene, whose mutations are frequent in colon cancers. The carcinogenetic mechanisms of the small-intestinal cancer we experienced may thus differ from those of colon cancers.

Endoscopy in the diagnosis of small intestinal tumors.

The importance of endoscopy in the diagnosis of small intestinal tumors was evaluated in 15 patients with small intestinal tumors treated in our hospital. Two tumors were benign, and 13 were malignant (carcinoma in 5 patients, malignant lymphoma in 5 and leiomyosarcoma in 3). The presence of lesions could be determined by X-rays before surgery, but definitive diagnoses were difficult. When preoperative endoscopy of the small intestine was possible accurate preoperative diagnoses could be made based on the endoscopic findings and biopsies taken under direct vision. Endoscopy is therefore very important for the diagnosis of small intestinal tumors. It is necessary to develop small intestinal endoscopes that are easier to insert.

Electronic Endoscopy in Endoscopic Mucosal Resection(EMR) of Gastric Cancer

The role in which electronic endoscopy plays is important in EMR. It is useful in diagnosis and treatment of gastric cancer from a clinical viewpoint. EMR with use of electronic endoscopy allows better coordination between the operator and assistants, and thus improves the results further.

Study on the optimal interval of monitoring following gastric polyp.

The present study was conducted to determine how long hyperplastic polyps (HPs) and fundic gland hyperplastic polyps (FGPs) should be endoscopically followed up. Our findings showed that in the case of FGPs, yearly endoscopy is not required and it is sufficient to repeat X-ray and compare films with those obtained in the previous year. In contrast, yearly follow-up by endoscopy is necessary in the case of HPs.

Fundamental and clinical studies of endoscopic Nd:YAG laser balloon irradiation for early gastric cancer

Since 1981, we have been employing endoscopic Nd:YAG laser irradiation for treatment of early gastric cancer. However, the therapeutic results have not always been satisfactory. Therefore, we have developed a new Nd:YAG laser-irradiation method which uses an endoscope fitted with a transparent thin-membrane balloon at its tip. Basic studies on this balloon method confirmed that the balloon did not affect the tissue-destructive effect of the laser. In clinical studies, the balloon method was used to treat 20 lesions. The degree of efficacy (effective: negative against cancer for at least one year after treatment) was 90%. Thus, in comparison with the conventional method, the balloon method produced clearly better therapeutic results.