Microsatellite instability in Korean patients with gastric adenocarcinoma.

OBJECTIVES: Microsatellites are short repeated oligonucleotide sequences found throughout the human genome. High mutation rates in microsatellite sequences have been found in tumors from patients with hereditary non-polyposis colorectal carcinoma and some sporadic carcinomas. However, little information is available regarding RER-positive phenotype in gastric carcinomas, particularly in terms of age of onset and other pathologic features, such as histologic types, degree of differentiation, location or stage of the carcinoma. METHODS: To obtain a better understanding of the molecular mechanism of gastric carcinogenesis, microsatellite instability was examined at 6 gene loci (D2S71, D2S119, D3S1067, D6S87, D8S87, D11S905) in 77 gastric carcinomas (40 cases of young patients and 37 cases of elderly patients). RESULTS: RER-positive phenotypes were found in 17 (22.1%) of 77 cases. In young patients (under 40 years) RER-positive phenotype was found in 9 (22.5%) of 40 cases, and in elderly patients 8 (21.6%) of 37 cases. Moderately differentiated carcinoma revealed a significantly high frequency of RER-positive phenotype than well differentiated carcinoma(p < 0.001). Tumors arising from the middle third (p < 0.001) or lower third (p < 0.001) revealed higher frequency of RER-positive phenotype than the tumors arising from the upper third of the stomach. The RER-positive phenotype was not significantly affected by the sex, histologic type or stage of carcinoma. CONCLUSION: RER-positive phenotype occurs frequently in gastric carcinoma, although the frequency of RER-positive phenotype between young and elderly patient was not significantly different. Thus, the acquisition of RER-positive phenotype might be an early event in gastric carcinogenesis.

Gastric juice ammonia vs CLO test for diagnosis of Helicobacter pylori infection.

The aim of the present study was to compare the gastric juice ammonia test to the CLO test for the diagnosis of H. pylori infection in culture-proven cases by receiver operating characteristic (ROC) curve analysis. We studied 75 subjects (44 with chronic gastritis, 10 with gastric ulcer, 6 with duodenal ulcer, 8 with gastric cancer, and 7 normal) by endoscopy with biopsy for tissue diagnosis, culture of H. pylori. CLO test, and by gastric juice ammonia determinations. The culture-positive group had significantly higher intragastric ammonia levels (13.7 +/- 5.8 mg/dl) than the negative group (4.9 +/- 2.4 mg/dl, P < 0.01). In ROC curve analysis, the gastric juice ammonia test showed higher true positive and lower false positive ratios than the CLO test (P < 0.05). In conclusion, the measurement of intragastric juice ammonia levels was considered to be simpler, quicker, and overall a more valuable method for diagnosing H. pylori infection.

Differentiation of malignant from benign pancreatic mass by Tl-201 abdominal SPECT.

The aim of the present study was to evaluate the ability of Tl-201 abdominal SPECT to differentiate between chronic focal pancreatitis and pancreatic malignancy. Seventeen patients (12 men, 5 women; mean age, 56 years; 9 pancreatic cancer, 8 chronic pancreatitis) with pancreatic mass were prospectively investigated with Tl-201 abdominal SPECT. In all patients, CT and/or US could not clarify the nature of the pancreatic mass. Focal hot uptake was present in 8 of 9 patients with pancreatic cancer, while it was present in 2 of 8 patients with chronic pancreatitis. Therefore, the sensitivity and specificity of the present study were 89% and 75%, respectively. A significant difference of Tl-201 uptakes was noted between benign and malignant masses (p < 0.05). Therefore, we concluded that Tl-201 abdominal SPECT was a useful test in differentiation of malignant from benign pancreatic mass, especially when the differentiation could not be made by other imaging modalities.

A double-blind, randomized, parallel group study of omeprazole and ranitidine in Korean patients with gastric ulcer.

The efficacy of the proton pump inhibitor omeprazole, 20 mg every morning, was compared with that of the H2-receptor antagonist ranitidine, 150 mg every morning and at bedtime, in a double-blind randomized parallel group study in 250 patients with gastric or prepyloric ulcers. At both 4 and 8 weeks, significantly more patients had healed ulcers in the omeprazole group than the ranitidine group, whether the results were analysed on a per-protocol or an intention-to-treat basis. At 4 weeks, 74% of patients in the omeprazole group were healed compared with 51% in the ranitidine group (P = 0.001), and at 8 weeks the corresponding values were 99 and 82% (P = 0.001, per-protocol cohort). Omeprazole treatment and small ulcer size significantly increased the probability of healing, but smoking had no significant effect. Patients in the omeprazole group had significantly fewer occurrences of daytime epigastric pain during the first 4 weeks than the ranitidine group (P = 0.0037), as shown by their diary cards. Both treatments were well tolerated.

Autoradiographic and immunohistochemical study on the proliferative kinetics of intestinal metaplasia.

In order to elucidate the proliferative behavior of the intestinal metaplasia around gastric cancer, the authors used both in vitro tritiated thymidine (3H-thymidine) autoradiography and in vivo bromodeoxyuridine (BrdUrd) immunohistochemistry for labeling the proliferative cells of the normal pyloric glands and metaplastic gastric glands. The results of the methods were comparable: The labeling pattern and the rate of labeling were very similar. In the normal pyloric mucosa, the labeled cells were confined to the isthmus region, indicating that pyloric glandular cells are normally renewed from the isthmus region. On the other hand, a zone of the labeled cells was found in the lower half of the intestinalized mucosa, indicating that cell proliferation took place deep in the mucosa, just like the case of normal intestinal glands. The labeling indices of the pyloric mucosa were 19.4% by autoradiography and 18.0% by immunohistochemistry, and that of the intestinalized gastric glands were 25.2% by autoradiography and 24.2% by immunohistochemistry. In conclusion, both 3H-thymidine autoradiography and BrdUrd immunohistochemistry showed that the proliferative kinetics of the intestinalized gastric glands was similar to that of the normal intestinal glands rather than the pyloric glands, i.e. a lower level of proliferative zone and higher labeling index were present.

Evaluation of omeprazole as a treatment for gastric and prepyloric ulcer in Korean patients.

The healing efficacy of omeprazole was assessed in 57 Korean patients with endoscopically-proven gastric (GU) and/or prepyloric (PPU) ulcers of at least 5 mm diameter. Fifty-three patients presented with GU, two with PPU and two with both types of ulcer. The maximum ulcer diameter was 5-10 mm in 27 patients and greater than 10 mm in 30 patients. All patients received 20 mg of omeprazole each morning for 4-8 weeks depending on ulcer healing. Ulcer healing rates were comparable using both 'intention to treat' (IT) and 'per protocol' (PP) analyses. Following the IT approach 82% (47 of 57) of patients were healed at 4 weeks and 98% (56 of 57) at 8 weeks. Following the PP approach, the corresponding healing rates were 83% (44 of 53) and 98% (55 of 56), respectively. Smoking was found to have a significant effect on ulcer healing at 4 weeks (P = 0.03), with 96% (26 of 27) of non/occasional smokers healed versus only 69% (18 of 26) of daily/heavy smokers. Ulcer size did not have a significant effect on healing, however. Ulcer symptoms, reported by all patients at entry, disappeared rapidly after commencement of omeprazole therapy. Only four patients reported mild symptoms at 4 weeks and no symptoms were reported at 8 weeks. No clinically significant changes in haematology or clinical chemistry (other than a rise in leucocytes in one patient) and no serious adverse events were observed. In conclusion, omeprazole 20 mg each morning was found to be safe and highly effective for treatment of gastric and prepyloric ulcer in Korean patients, producing a 98% healing rate. Symptom relief was rapid and the drug was well tolerated.

Early gastric cancer in Korea.

We reviewed the 639 cases of early gastric cancer from nation-wide 16 medical centers. The proportion of early gastric cancer among surgically resected gastric carcinoma comprised 6 to 12 percent. Male to female ratio was 1.7 to 1 with male preponderance. Mean ages of the early gastric cancer was 49.0 years and most prevalent ages was 5th decade. Macroscopically type IIc was most prevalent, reaching 59.9 percent. Depressed type lesions was more frequent than elevated type lesions by four folds. The size of lesions less than 4 cm accounted for more than 80 percent. Most frequent site of lesions were lower third by the CMA classification and lesser curvature transectionally. Lymph node metastasis was observed in 10.9 percent of all cases and it was more frequent in large tumor size more than 4 cm, elevated type, and undifferentiated carcinoma. 5-year survival rate was 91.6 percent. Gastrofiberscopic examination was superior to that of radiological examination in the diagnosis of early gastric cancer.

Clinical features of Crohn's disease in Korea.

Crohn's disease is a rare disease in Korea, and only 45 cases have been reported during the period of 34 years from 1952 to 1985. The male to female ratio was about 1.3 to 1 with a slight preponderance of males. The age at diagnosis ranged from 8 to 72 (mean 35.5) years, and the peak incidence occurred in the 3rd, 4th and 5th decades and declined thereafter. More than two thirds of the cases had a grossly demonstrable lesion involving the small bowel, including the terminal ileum. The proportion of patients with macroscopic disease continued to the large bowel alone was only 15%. Abdominal pain was common, presenting in 89% of the patients, while such symptoms as fever, hematochezia and diarrhea were not common. Abdominal mass was palpable in more than half the cases, which made it difficult to differentiate Crohn's disease from cancer of the colon, especially in cases with a predominant infiltration of the bowel wall and a secondary ulcer formation. That is one of the reasons why most cases in Korea have been reported by surgeons. A wide variety of complications were present, of which small bowel obstruction was the most common. Other complications were free perforation, malnutrition, fistula formation, hemorrhage and abscess formation, in decreasing order. The incidence of symptomatic perianal disease was only 11%, and this might be due to the small proportion of the disease confined to large bowel. Extraintestinal manifestations were also rare, and only three patients presented symptoms of arthritis. Other systemic features such as liver disease, skin lesion, eye complications were absent.