• Journal of Gastric Cancer
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• v.3 no.1
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• pp.50-55
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• 2003

Background: An aberrant function of the mismatch repair system has been reported to underlie carcinogenesis in several tumors, including colorectal and gastric carcinomas, and to induce the typical genotype of microsatellite instability (MSI). Purpose: We aimed to determine the frequency of MSI in early-onset sporadic gastric carcinoma and elucidate the role of promoter methylation in hMLH1 as the mechanism of MSI. Materials and Methods: Thirty-six early-onset sporadic gastric carcinomas were analyzed to determine the status of MSI and the frequency of methylation of the promoter region in hMLH1. MSI was determined using five markers recommended by NCI: MSI-H (high), MSI-L (low), and MSS (Microsatellite stable). Methylation specific PCR (MSP) and direct automated genomic sequencing analysis with DNA modified by sodium bisulfite have been performed to confirm promoter region methylation. All the data were analyzed regarding characteristics of molecular changes, and clinicopathologic variables. Results: The microsatellite status was determined as MSI-H in five cases ($13.8\%$), MSI-L in 13 cases ($36.1\%$), and MSS in 18 cases ($50.0\%$). hMLH1 was methylated in seven cases ($19.4\%$). In all cases of MSI-H, promoter of hMLH1 was methylated, and in two of the 13 cases of MSI-L, hMLH1 promoter methylation was identified. Methylation was not found in any cases of MSS. Promoter methylation in hMLH1 was significantly correlated with MSI status (P<0.001). We could not find any relationship between MSI and clinicopathologic parameters. Conclusion: These results suggest that an abnormal function of the mismatch repair system may be associated with gastric carcinogenesis in more than $10\%$ of early-onset gastric carcinomas and MSI appeared to be closely related to the promoter methylation in hMLH1.

• Journal of Gastric Cancer
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• v.3 no.1
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• pp.26-32
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• 2003

Purpose: Genomic alterations and abnormal expression of the fragile histidine triad (FHIT) gene in gastric cancer were examined to determine whether the FHIT gene is actually a frequent target for alteration during gastric carcinogenesis. Materials and Methods: To correlate DNA and RNA lesions of the FHIT gene with the effect on FHIT protein expression, in 40 gastric cancers, we investigated the FHIT gene for loss of heterozygisity (LOH), aberrant transcripts, and protein expression. Results: Allelic loss at D3S1300 was detected in 7 of 38 ($19\%$) informative cases. Aberrant transcripts were observed in 20 of 40 ($50\%$) cases. Significant reduction of FHIT protein expression was observed in 22 of 40 ($55\%$) cases. Aberrant FHIT transcription was shown to be associated with loss of FHIT protein expression. However, aberrent FHIT transcripts themselves were not associated with any clinicopathological parameters, such as age, sex, tumor site, or clinical stage. Moreover, there was no association between the presence of LOH at D3S1300 and the expression of aberrant FHIT transcripts. Conclusion: The high frequency of aberrant FHIT transcripts, the significant rate of LOH at D3S1300, and the altered expression of the FHIT protein indicate that alterations of the FHIT gene can play an important role in gastric carcinogenesis.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.181-188
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• 2006

Purpose: Heregulin is a natural ligand for erbB3 and erbB4. However, very little is known about their roles in the gastric cancer This retrospective study was performed to evaluate the frequencies of heregulin and erbB family protein expression and to compare their expressions with clinicopathologic parameters. Materials and Methods: Immunohistochemical expressions of heregulin and erbB family proteins were examined with tissue micro-array slides. A total of 251 gastric adenocarcinomas were classified as early cancers and advanced cancers and as having and not having lymph node metastases. Results: The positive rates of the heregulin, erbB1, erbB2, erbB3, and erbB4 protein stainings were 64%, 68%, 6%, 88%, and 76%, respectively. Intestinal type gastric adenocarcinomas showed higher expression of heregulin, erbB2, erbB3, and erbB4 proteins. Heregulin and erbB4 proteins showed lower expressions in advanced gastric carcinomas. However, erbB2 protein showed higher expression in advanced gastric carcinomas. The protein expressions of heregulin and erbB family proteins showed no relationship with survival rate. Co-expression groups of heregulin and erbB3 proteins or heregulin and erbB4 proteins showed higher expressions in intestinal type adenocarcinomas and early gastric carcinomas. Conclusion: Heregulin, erbB3, and erbB4 proteins may play a role in the early stage of adenocarcinomas.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.193-199
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• 2009

Purpose: The aim of this study was to evaluate the clinicopathologic features, treatment outcomes, and prognostic factors of gastric cancer based on 14 years' experience in a single medical center, and to compare treatment outcomes with a previous study. Materials and Methods: We retrospectively studied 2,327 patients who were operated on for gastric cancer between 1993 and 2006 at Korea University Hospital. Results: The resection rate was 92.8% and curative resection was achieved for 1,960 (90.8%) patients. The 5-year survival rate was 70.0% for all patients undergoing resection and 79.2% for patients undergoing curative resection. The 5-year survival rate was 1.5% for unresected cases. Age, tumor size, location of the tumor, gross tumor type, depth of tumor invasion, lymph node involvement, distant metastasis, tumor stage, combined resection, complications, histology, and type of operation each had prognostic significance on univariate analysis. On multivariate analysis, lymph node involvement, depth of invasion, venous invasion, and age were independent prognostic factors. Conclusion: The 5-year survival rate for patients who underwent curative resection was 79.2%. Depth of invasion, lymph node involvement, venous invasion, and age were independent prognostic factors. The fact that tumor stage is the most important prognostic factor after curative resection, increases the importance of early detection.

• Journal of Gastric Cancer
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• v.8 no.1
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• pp.47-52
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• 2008

The majority of choriocarcinomas occur in the uterus as gestational malignant tumors. Rarely, a choriocarcinoma appears in the gastrointestinal tract, and the tumor is assumed to arise from a different histogenetic origin as compared to tumors of other sites. A primary gastric choriocarcinoma is a rare aggressive, widely metastatic malignant tumor, and has a poor prognosis. Reported here is a case of a 69-year-old woman with a primary gastric choriocarcinoma who presented with melena, epigastric pain, and was diagnosed with a poorly differentiated adenocarcinoma based on a preoperative endoscopic biopsy. Gastrectomy with lymph node dissection, followed by postoperative chemotherapy, is the treatment of choice. Therefore, in the case of a poorly differentiated adenocarcinoma with a bleeding tendency, a meticulous examination with the suspicion of a choriocarcinoma should be undertaken.

• Journal of Aquaculture
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• v.17 no.3
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• pp.215-220
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• 2004

Using light microscopy, the digestive tract of the parrot fish, Oplegnathus fasciatus was studied histologically. The tract consists of esophagus, stomach, intestine and fifty or sixty pyloric caecae. Each pyloric caecum is a blind sac of banana shape, and is originated from pyloric end of the stomach. The relative length of gut (RLG), that is length of digestive tract to standard length, is 1.78 (n=30). Esophagus has an undeveloped submucosa and a well developed muscularis mucosae. Its mucosa displays primary and secondary folds lined with a cuboidal or columnar epithelium and numerous acidic mucous secretory cells. The stomach has muscularis, which consists of longitudinal and circular muscular layers; its submucosa and muscularis mucosae are well developed. Only primary folds are present in the stomach. Microvilli are present in the epithelial layer. The stomach has a well-developed gastric gland and relatively more secretory granules. Mucosal epithelium of the pyloric caeca is composed of neutral mucous secretory cells and columnar epithelium with developed microvilli in the apical portion. Using the morphological and histological features, the intestine may be divided into anterior, mid and posterior parts. It has an advanced striated border and abundant acidic mucous secretory cells and some neutral mucous secretory cells. The mid intestine has more abundant acidic mucous secretory cells than the anterior and posterior parts. A thick longitudinal muscle is formed in the intestine and its thickness is progressively increased towards the posterior end.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.252-259
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• 2005

To clarify the clinicopathologic features of small-cell carcinomas (SCC) of the stomach, we reviewed three cases of surgically treated SCC. The first case was a pure SCC, with severe pancreatic invasion and peritoneal seeding. A gastro-jejunostomy was performed. Postoperative chemotherapy was performed with CDDP and VP-16 (8 cycles) but showed disease progression (PD); a consecutive chemotherapy with CDDP and irinotencan (2 cycles) also showed PD. A third line with CDDP, VP16, ifosfamide, and mesna was followed by a 4th line (CDDP and Taxol). The male patient died with liver metastasis and peritoneal seeding 14 months after the operation. The second case was a SCC mixed with a poorly differentiated adenocarcinoma. Profound lymphadenopathy and liver metastasis were found. Two cycles of preoperative chemotherapy with TS-1 and CDDP were performed, which showed nearly complete remission for lymphadenopathy and partial response for the primary tumor site and liver metastatic lesion. A total gastrectomy and extended lymphadenectomy was performed. There were no viable cancer cells in 35 retrieved lymph nodes. Postoperative chemotherapy using the same regimen was performed for 4 cycles. Enlarged liver metastasis was found at the follow-up CT scan, so a posterior segmentectomy of liver was performed. After liver surgery, the chemotherapy regimen was changed to irinotecan and cisplatin. This male patient has been in good health for the f4 months since gastric surgery. The third case was a pure SCC, and a subtotal gastrectomy was performed curatively. That male patient received 5 cycles of TS-1 and is still in good health 14 months after operation.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.115-127
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• 1998

The digestive tract of the rockfish, Sebastes schlegeli composed of pharynx, esophagus, stomach, intestine, anus and ten or eleven pyloric caeca. Pyloric caeca is blind sac of banana shape, and that is originated from pyloric portion of the stomach. The relative length of gut(RLG), that is length of digestive tract to standard length, is about 1.56(n=10). Esophageal muscularis consists of thin outer layer of longitudinal muscle and thick inner layer of circular muscle. Mucosal epithelium consists of columnar epithelium with short microvilli and contains numerous mucous secretory cell. The mucosal folds of the stomach are regular, and the muscularis consists of longitudinal, oblique and circular muscle layer. The chief cell of the gastric gland have a tubular mitochondria, endoplasmic reticula and numerous secretory granules in electron-dense. However, parietal cell contains small mitochondria, endoplasmic reticula and vacuoles in low electron density. Mucosal epithelium of the pyloric caeca and intestine composed of columnar epithelium, goblet cell, rodlet cell and dark cell. Columnar absorptive cell in the pyloric caeca and intestine contains well developed mitochondria, endoplasmic reticula, vesiculated granules in high electron density, pinocytotic vesicles and multivesicular body. Rodlet cell have a well developed cytoplasmic capsule and the endoplasmic reticula in the cytoplasm. Dark cell showing a high electron density in the cytoplasm and contains well developed mitochondria. Columnar epithelium of the intestine have a well developed intercellular junction and the microvilli which contains actin filament originated from the cytoplasm. Mucosal epithelium of the intestine have a longer microvilli and more abundant goblet cells than in the pyloric caeca.

• Parasites, Hosts and Diseases
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• v.29 no.2
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• pp.149-160
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• 1991

Each of SPF mice(Scl: ICR strain, 3-week-old males) was inoculated with 5$\times$104 oocysts of Cryptosporidium by stomach tube. The oocysts were large type one which was previously isolated from Korean mice, and passaged in 3-week-old SPF mice. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of developmental stages the stomach of the mice was examined by transmission electron microscopy (TEM) at 4 weeks post-inoculation. The prepatent period for 6 mice was 5.6 days post-inoculation on the average, and the patent period was 63.2 days. The number of oocysts discharged per day from the mice reached peak on day 36.6 post-inoculation on the average. A large number of oocysts were found in fecal samples obtained from inoculated mice on days 30~50 post-inoculation. C. tsuris was larger than C. parvum at almost every developmental stages, the sixte difference being 1.4 times in oocysts, 2.4 times in sporozoites, 1.6 times in merozoites, and 1.5 times in microgametes. The ultrastructural features of the attachment site of C. tsuris to the mucus cells were remarkably different from those of C. parvum and its closely related species. The anterior projection of the protozoa (C. muris), the outer aspect of which was surrounded by a thick filamentous process of the host cell, has not been reported at any developmental stages of C. parvum or its closely related species. The size of the oocysts of strain RN 66 was larger than that of Korean mice origin. The above results reveal that the large type Cryptosporidium of Korean mice origin is identified as Cryptosporidium muris and this type was named as C. muris (strain MCR).

• Korean Journal of Ichthyology
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• v.10 no.2
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• pp.207-215
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• 1998

Just after hatching the embryo has a yolk sac and straighted digestive tract. Just after parturition in 5.0mm TL the mouth and anus were opened. In the larval stage of 5.2mm TL, digestive tract could be divided into pharynx, esophagus, stomach, pyloric caeca and intestine of the early differentiated state. The esophagus of larvae in 5.3mm TL has a PAS positive mucous cell. From over 5.7mm TL, PAS positive goblet cell recognized in the intestine. PAS positive absorptive cell began to appear in the intestine from 5.9mm TL. Yolky materials were absorbed completely in 6.0mm TL. In the larvae of B.5mm TL, gastric glands were observed in the mucosa, but the surface epithelium did not have PAS positive granules. From over 9.0mm TL, the histological structure of esophagus showed similar to adult. In the juvenile stage from 13.0mm to 15.0mm TL, histological structure of the stomach, pyloric caeca and intestine showed similar to adult. From the ultrastructural and histochemical study, it is concluded that the functional digestive tract is present in the juvenile stage from 18.0mm to 20.0mm TL.