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Biomedical subjects

I S Song

Publications and source records attributed to I S Song.

At least 19 recordsLinked to original sources

Omeprazole may be superior to famotidine in the management of iatrogenic ulcer after endoscopic mucosal resection: a prospective randomized controlled trial.

BACKGROUND: Acid suppressing agents are widely used to treat the iatrogenic ulcers following endoscopic mucosal resection for gastric neoplasms. However, the relative merits of proton pump inhibitor or histamine(2)-receptor antagonist for endoscopic mucosal resection-induced ulcers are not known. AIM: To prospectively compare omeprazole and famotidine for the healing of endoscopic mucosal resection-induced ulcers and for bleeding control. METHODS: After endoscopic mucosal resection, patients were randomly assigned to omeprazole (20 mg/day) or to famotidine (40 mg/day) group for a 28-day treatment period. The ulcer sizes and stages, bleeding rates and ulcer-related symptoms were compared. RESULTS: A total of 100 patients were randomized equally to each group. Forty-one patients in each group were finally compared. The two groups were comparable in terms of baseline characteristics. Twenty-eight days after treatment, the two groups were not different with respect to ulcer stage (P = 0.137) or ulcer reduction ratio (P = 0.380). No difference was observed with respect to ulcer-related symptoms (P = 0.437) and no bleeding episode occurred in any of the 82 patients. In subgroup that underwent endoscopic submucosal dissection, fewer patients in the omeprazole group showed active ulcers than those in the famotidine group (P = 0.035). CONCLUSION: Our results demonstrate that omeprazole may be superior to famotidine for iatrogenic ulcers following endoscopic mucosal resection, especially for large ulcers.

Anti-Ulcer Agents↗

Intraoperative gastroscopy for gastric surgery.

BACKGROUND: Few reports are available on the use of intraoperative gastroscopy for gastric surgery. METHODS: The details of 33 patients (25 early gastric cancers and eight gastric submucosal tumors) who underwent intraoperative gastroscopy from June 2003 to June 2004 were analyzed. The type of operation or resection margin was determined by evaluating both sides of the stomach simultaneously by combined operative and gastroscopic methods. RESULTS: Preoperative endoscopic clipping was done preferentially for early gastric cancer. However, when precise localization was needed, intraoperative gastroscopy was used. Curative gastric resection was possible in 25 early gastric cancer patients after accurate lesion localization. Laparoscopic wedge resections of submucosal tumors were performed in seven patients without stenosis by combined laparoscopic and gastroscopic methods. CONCLUSIONS: Intraoperative gastroscopy can be used effectively during gastric surgery for early gastric cancer or submucosal tumors and can be regarded as a modern stethoscope to gastric surgeons.

Gastric Mucosa↗

Primary colon lymphoma in Korea: a KASID (Korean Association for the Study of Intestinal Diseases) Study.

Although almost all primary colorectal lymphomas are of B-cell lineage in Western countries, primary colorectal T-cell lymphomas are not uncommon in the East. The aim of this study was to review the clinical characteristics and treatment outcomes of primary colorectal lymphomas, with special emphasis on the differences between T-cell and B-cell lymphomas. Ninety-five cases of primary colorectal lymphomas that satisfied Dawson's criteria were identified from the clinical databases of 13 university hospitals in Korea. The mean age at the time of presentation was 51.1 years and the male:female ratio was 64:31. The clinical information, including endoscopic and histological characteristics, was retrospectively analyzed. Of the primary colorectal lymphomas, 78 cases (82.1%) were of B-lineage and 17 cases (17.9%) were of T-cell lineage. Patients with T-cell lymphomas presented at a younger age than patients with B-cell lymphomas (42.8 vs 52.9 years, respectively; P = 0.016). The most common presenting symptom was abdominal pain (87.1%) for B-cell lymphomas, whereas hematochezia or night fever was more common for T-cell lymphomas (52.9% and 35.3%, respectively). The most common endoscopic type was fungating mass (54.0%) for B-cell lymphomas and ulcerative/ulcero-infiltrative lesions (80.0%) for T-cell lymphomas. Intussusception was more common in B-cell lymphomas than in T-cell lymphomas (30.8% vs 5.9%, respectively; P = 0.035), but perforation was more common in T-cell lymphomas than in B-cell lymphomas (23.5% vs 3.8%, respectively; P = 0.005). The prognosis was significantly worse for T-cell lymphomas than for B-cell lymphomas (P = 0.002). Primary colorectal T-cell lymphomas are characterized by multifocal ulcerative lesions in relatively young patients, a high rate of hematochezia, fever, or perforation, and a poor prognosis even for cases of localized disease.

Adolescent↗

Is a 9-month treatment sufficient in tuberculous enterocolitis? A prospective, randomized, single-centre study.

BACKGROUND: Tuberculosis has increased in parallel with the acquired immunodeficiency syndrome epidemic and the use of immunosuppressive therapy, and the growing incidence of extra-pulmonary tuberculosis, especially with intestinal involvement, reflects this trend. However, the duration of anti-tuberculous therapy has not been clarified in intestinal tuberculosis. AIM: To compare the efficacy of different treatment durations in tuberculous enterocolitis in terms of response and recurrence rates. METHODS: Forty patients with tuberculous enterocolitis were randomized prospectively: 22 patients into a 9-month and 18 into a 15-month group. Diagnosis was made either by colonoscopic findings of discrete ulcers and histopathological findings of caseating granuloma and/or acid-fast bacilli, or by clinical improvement after therapeutic trial. Patients were followed up with colonoscopy every other month until complete response or treatment completion, and then every 6 months for 1 year and annually. Complete response was defined as a resolution of symptoms and active tuberculosis by colonoscopy. RESULTS: Complete response was obtained in all patients in both groups. Two patients in the 9-month group and one in the 15-month group underwent operation due to intestinal obstruction and perianal fistula, respectively. No recurrence of active intestinal tuberculosis occurred during the follow-up period in either group. CONCLUSIONS: Tuberculous enterocolitis can be managed by 9-month chemotherapy without disease recurrence. Further investigations are needed in immunocompromised patients.

Adult↗

The effect of rebamipide on the expression of proinflammatory mediators and apoptosis in human neutrophils by Helicobacter pylori water-soluble surface proteins.

BACKGROUND: Helicobacter pylori infection elicits persistent neutrophil infiltration in gastric mucosa. The expression of cyclooxygenase (COX)-2 and inhibition of apoptosis in the neutrophils could contribute to the pathogenesis of H. pylori infection. Rebamipide, a mucosal protective and ulcer-healing drug, has been known to inhibit neutrophil activation. AIM: To evaluate the effect of rebamipide on the neutrophils activated by H. pylori water-soluble proteins. METHODS: After neutrophils were stimulated with H. pylori water extract (HPWE) or pre-treated with rebamipide, the expression of COX-2 mRNA and protein was assessed by quantitative RT-PCR and Western blotting, respectively. Prostaglandin (PG) E2 synthesis was determined by radioimmunoassay. Neutrophil apoptosis was evaluated by cytosolic oligonucleosome-bound DNA ELISA and caspase-3 activity was measured by the detection of p-nitroanilide after cleavage from labelled substrate. RESULTS: Stimulation with HPWE up-regulated COX-2 expression and PGE2 secretion, and inhibited neutrophil apoptosis. Rebamipide suppressed PGE2 secretion from neutrophils dose-dependently. Rebamipide, however, did not affect neutrophil apoptosis and caspase-3 activity. CONCLUSIONS: Rebamipide effectively suppressed PGE2 secretion from neutrophils activated by H. pylori water-soluble proteins. This is another possible mechanism of gastric mucosal protection by rebamipide.

Alanine↗

Survey of nitrate and nitrite contents of vegetables grown in Korea.

A scientific basis for the evaluation of the risk to public health arising from excessive dietary intake of nitrate in Korea is provided. The nitrate () and nitrite () contents of various vegetables (Chinese cabbage, radish, lettuce, spinach, soybean sprouts, onion, pumpkin, green onion, cucumber, potato, carrot, garlic, green pepper, cabbage and Allium tuberosum Roth known as Crown daisy) are reported. Six hundred samples of 15 vegetables cultivated during different seasons were analysed for nitrate and nitrite by ion chromatography and ultraviolet spectrophotometry, respectively. No significant variance in nitrate levels was found for most vegetables cultivated during the summer and winter harvests. The mean nitrates level was higher in A. tuberosum Roth (5150 mg kg(-1)) and spinach (4259 mg kg(-1)), intermediate in radish (1878 mg kg(-1)) and Chinese cabbage (1740 mg kg(-1)), and lower in onion (23 mg kg(-1)), soybean sprouts (56 mg kg(-1)) and green pepper (76 mg kg(-1)) compared with those in other vegetables. The average nitrite contents in various vegetables were about 0.6 mg kg(-1), and the values were not significantly different among most vegetables. It was observed that nitrate contents in vegetables varied depending on the type of vegetables and were similar to those in vegetables grown in other countries. From the results of our studies and other information from foreign sources, it can be concluded that it is not necessary to establish limits of nitrates contents of vegetables cultivated in Korea due to the co-presence of beneficial elements such as ascorbic acid and alpha-tocopherol which are known to inhibit the formation of nitrosamine.

Allium↗

Effect of Helicobacter pylori eradication on duodenal ulcer scar in patients with no clinical history of duodenal ulcer.

BACKGROUND: Helicobacter pylori eradication has become the standard treatment for duodenal ulcer. However, there is no relevant evidence for antibacterial treatment of the white scar stage of duodenal ulcer (duodenal ulcer scar) in patients with no past history of duodenal ulcer. AIM: To investigate whether H. pylori eradication could decrease duodenal ulcer recurrence in patients with duodenal ulcer scar and no past history of duodenal ulcer. PATIENTS AND METHODS: We prospectively enrolled 66 patients with duodenal ulcer scar: 53 were H. pylori-positive and 13 were H. pylori-negative. H. pylori-positive patients were randomly assigned into two groups (two-to-one allocation): 36 patients were assigned to the treatment group and 17 to the follow-up group. Thirteen H. pylori-negative patients were followed up according to the study protocol. Follow-up endoscopy was performed to evaluate ulcer scar changes and H. pylori status 6 weeks after anti-H. pylori treatment and then every 6 months for up to 30 months. RESULTS: Active duodenal ulcer recurrence was identified in seven of 23 H. pylori-positive/non-cured patients (30%). There was no duodenal ulcer recurrence in 43 H. pylori-negative/cured patients (0%), which was significantly different in terms of duodenal ulcer recurrence (P=0.001). CONCLUSIONS: H. pylori eradication is effective at preventing active duodenal ulcer recurrence in patients with duodenal ulcer scar and no past history of duodenal ulcer.

Amoxicillin↗

Expression of cyclooxygenase-2 in human neutrophils activated by Helicobacter pylori water-soluble proteins: possible involvement of NF-kappaB and MAP kinase signaling pathway.

Helicobacter pylori infection elicits persistent neutrophil infiltration in gastric mucosa. The expression of cyclooxygenase (COX) -2 by the neutrophils results in prostaglandin (PG) E2 synthesis, which may account for alterations in tissue homeostasis. In this study, we found that COX-2 mRNA was up-regulated in the neutrophils when stimulated with both H. pylori water extract (HPWE) and live H. pylori in a transwell model and determined by quantitative RT-PCR. PGE2 synthesis was also enhanced in the neutrophils activated by both the HPWE and live H. pylori. A specific COX-2 inhibitor (NS-398) blocked PGE2 synthesis, and an anti-ulcer agent (rebamipide) suppressed it dose dependently. An NF-kappaB inhibitor (pyrrolidine dithiocarbamate), a MAP kinase (MEK) inhibitor (PD98059), and a p38 MAP kinase inhibitor (SB203580) significantly suppressed the COX-2 gene transcription and PGE2 synthesis in the neutrophils. In conclusion, H. pylori water-soluble proteins may enhance the COX-2 expression, and this action could be mediated through the NF-kappaB and MAP kinase signaling pathways. The increased section of PGE2 by the neutrophils may play a proinflammatory role in the gastric mucosal response to H. pylori.

Bacterial Proteins↗

Caspase-3 activity and expression of Bcl-2 family in human neutrophils by Helicobacter pylori water-soluble proteins.

BACKGROUND: Persistent infiltration of neutrophils is an almost invariable feature of Helicobacter pylori-infected gastric mucosa. A prolongation of neutrophil life-span could contribute to the pathogenesis of H. pylori infection. Recently, we have demonstrated that H. pylori water extracts (HPWE) inhibited neutrophil apoptosis. To elucidate the regulation of intracellular apoptotic signals by HPWE, we examined the activity of caspase-8, -3 and expression of Bcl-2 family in neutrophils. MATERIALS AND METHODS: Human neutrophils were obtained from the peripheral blood of healthy volunteers by density gradient separation. HPWE was prepared from a supernatant of the H. pylori suspension in distilled water. After neutrophils were incubated with HPWE, expression of Bcl-2 family [antiapoptotic (Bcl-2, Bcl-XL and Mcl-1) and proapoptotic (Bax, Bak and Bcl-XS)] was determined by RT-PCR and Western blotting, respectively. Western blot for Bcl-2 family also performed in neutrophilic differentiated HL-60 cells by all-trans-retinoic acid. The activity of caspase-8, -3 was measured by the detection of p-nitroanilide after cleavage from labeled substrate. RESULTS: HPWE suppressed the activation of caspase-8 and -3, and upregulated the expression of Bcl-XL mRNA and proteins in neutrophils. The expression of Bax and Bak was upregulated and Bcl-2, Bcl-XL and Mcl-1 downregulated in HL-60 cells during neutrophilic differentiation. CONCLUSION: Bcl-XL may have an important role in the neutrophilic development and inhibition of neutrophil apoptosis by H. pylori.

Bacterial Proteins↗

Inhibition of apoptosis in human neutrophils by Helicobacter pylori water-soluble surface proteins.

BACKGROUND: Helicobacter pylori infection in humans causes persistent neutrophil infiltration into the gastric mucosa. It is believed that a prolongation of neutrophil life-span could contribute to the pathogenesis of H. pylori infection. We therefore examined whether the water-soluble surface proteins of H. pylori can influence the apoptosis of neutrophils. METHODS: After neutrophils were incubated with H. pylori water extract (HPWE), neutrophil apoptosis was evaluated by TUNEL assay, Hoechst 33342 staining, electron microscopy and ELISA for cytosolic oligonucleosome-bound DNA for up to 48 h. To investigate the regulatory mechanisms of neutrophil apoptosis associated with HPWE, mRNA expression and protein production of Fas, Fas ligand (FasL) and tumor necrosis factor receptor 1 (TNF-R1) were analyzed by RT-PCR, ribonuclease protection assay, Northern blot and Western blotting. Cell surface expression of these death factors was also measured by flow cytometry. RESULTS: HPWE inhibited neutrophil apoptosis and cytotoxicity for up to 48 h. The mRNA and protein expression of FasL and the cell surface expression of Fas, FasL and TNF-R1 in HPWE-treated neutrophils were suppressed compared with the controls. CONCLUSION: The water-soluble surface proteins of H. pylori could suppress neutrophil apoptosis. This may be caused by the suppression of FasL expression in neutrophils and Fas, FasL and TNF-R1 expression on the surface of neutrophils.

Apoptosis↗

Contribution of ion pair complexation with bile salts to biliary excretion of organic cations in rats.

The objective of this study was to examine whether ion pair complexation with endogenous bile salts in hepatocytes contributes to the preferential biliary excretion of organic cations (OCs). Tributylmethylammonium (TBuMA; mol wt 200) and triethylmethylammonium (TEMA; mol wt 116) were selected as model OCs that exhibit significant and negligible biliary excretion, respectively, in rats. The apparent lipophilicity of TBuMA, but not that of TEMA, was increased by the presence of either rat bile or specific bile salts, suggesting the formation of lipophilic ion pair complexes for TBuMA with bile salts in the liver. The uptake of TBuMA into canalicular liver plasma membrane (cLPM) vesicles, but not that of TEMA, was increased in the presence of bile salts, with a significant increase for both ATP-dependent transport and passive diffusion. The uptake of TBuMA in the presence of the bile salts was inhibited by representative P-glycoprotein (P-gp) substrates and vice versa, suggesting the involvement of P-gp in the canalicular excretion of TBuMA-bile salt complexes in vivo. Increased affinity toward P-gp is suggested as the mechanism responsible for the increased ATP-dependent transport for the ion pair complexes. We propose that ion pair formation with bile slats in hepatocytes may be responsible for the preferential biliary excretion of high-molecular-weight OCs including TBuMA.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Hepatopulmonary syndrome in poorly compensated postnecrotic liver cirrhosis by hepatitis B virus in Korea.

BACKGROUND: Hepatopulmonary syndrome (HPS) refers to the association of hypoxemia, intrapulmonary shunting and chronic liver disease. But there is no clear data about the prevalence of HPS in postnecrotic liver cirrhosis by hepatitis B virus (HBV), the most common cause of liver disease in Korea. The aim of this study was to investigate the prevalence of HPS in poorly compensated postnecrotic liver cirrhosis by HBV, and the correlation of the hepatopulmonary syndrome with clinical aspects of postnecrotic liver cirrhosis by HBV. METHODS: Thirty-five patients underwent pulmonary function test, arterial blood gas analysis and contrast-enhanced echocardiography. All patients were diagnosed as HBV-induced Child class C liver cirrhosis and had no evidence of intrinsic cardiopulmonary disease. RESULTS: Intrapulmonary shunt was detected in 6/35 (17.1%) by contrast-enhanced echocardiography. Two of six patients with intrahepatic shunts had significant hypoxemia (PaO2 < 70 mmHg) and four showed increased alveolar-arterial oxygen gradient over 20 mmHg. Only cyanosis could reliably distinguish between shunt positive and negative patients. CONCLUSIONS: The prevalence of intrapulmonary shunt in poorly compensated postnecrotic liver cirrhosis by HBV was 17.1% and the frequency of hepatopulmonary syndrome was relatively low (5.7%). 'Subclinical' hepatopulmonary syndrome (echocardiographically positive intrapulmonary shunt but without profound hypoxemia) exists in 11.4% of cases with poorly compensated postnecrotic liver cirrhosis by HBV. Cyanosis is the only reliable clinical indicator of HPS of HBV-induced poorly compensated liver cirrhosis. Further studies are required to determine if the prevalence and clinical manifestations of HPS varies with etiology or with geographical and racial differences.

Adult↗

Long-term clinical course and prognostic factors in intestinal Behçet's disease.

PURPOSE: The present study was aimed at evaluating the long-term course of intestinal Behçet's disease and determining predictive factors of prognosis. METHODS: This report is a retrospective study based on the records of 43 patients with intestinal Behçet's disease. The mean follow-up duration was 73 +/- 60 months. We evaluated the efficacy of medical treatment for the intestinal lesion at initial eight weeks. The cumulative probabilities were calculated by using Kaplan-Meier method, and the results were compared by using the log-rank test. RESULTS: Sixteen patients (38 percent) achieved a complete remission of intestinal lesions eight weeks after medical treatment had begun. The patients who achieved a complete remission had a lower probability of receiving an operation than those who had not (13 percent at 2 and 5 years vs. 36 and 43 percent, respectively; P = 0.028). The recurrence probability of intestinal lesions was 25 percent at two years and 49 percent at five years after complete remission with medical treatment. Patients who had a history of intestinal perforation or fistula had a higher probability of recurrence after operation than those without such history (59 vs. 33 percent at 2 years; 88 vs. 57 percent at 5 years; P = 0.020). Patients who had taken azathioprine had a lower probability of receiving reoperation than those who did not (7 vs. 25 percent at 2 years; 25 vs. 47 percent at 5 years; P = 0.035). The length of ileal resection and whether hemicolectomy was performed had no significant effect on the recurrence or reoperation rate. CONCLUSIONS: Intestinal Behçet's disease frequently requires a surgical treatment and has a high recurrence rate. The patients who achieved a complete remission with medical treatment, who had no history of intestinal perforation, and who received azathioprine after operation showed better clinical courses. Resection of a short segment of bowel would be a more appropriate surgical procedure.

Adolescent↗

Virulence factors of Helicobacter pylori in Korean isolates do not influence proinflammatory cytokine gene expression and apoptosis in human gastric epithelial cells, nor do these factors influence the clinical outcome.

The cytotoxin-associated gene (cagA) and vacuolating cytotoxin (Vac) production have been reported to be major virulence factors of Helicobacter pylori. However, there have been some disputes regarding the correlation between these virulence factors and clinical outcomes. We evaluated whether the cagA-positive genotype and Vac production might be correlated with various gastroduodenal diseases in Korea and whether this correlation could be due to differences in proinflammatory cytokine gene expression and apoptosis of gastric epithelial cells in vitro. The presence of the cagA gene was examined by the polymerase chain reaction (PCR), and Vac production was detected using the bacterial culture supernatant and HeLa cells after H. pylori was isolated from Korean patients. Gastric epithelial cells were infected with cagA+Vac+, cagA+Vac-, or cagA-Vac- strains, after which cytokine gene expression was evaluated, using quantitative reverse transcription (RT)-PCR. Apoptosis and caspase-3 activation were measured in H. pylori-infected gastric epithelial cells. There was no significant correlation between the presence of these virulence factors in H. pylori isolates and peptic ulcer or gastric cancer. Upregulation of cytokine gene expression, including that of interleukin (IL)-1alpha, IL-8, granulocyte macrophage colony-stimulating factor (GM-CSF), and monocyte chemotactic protein (MCP)-1, as well as apoptosis and caspase-3 activation, were similar in infections with cagA-positive and cagA-negative strains, but were not correlated with the production of Vac. These results suggest that the lack of correlation between virulence factors of isolated H. pylori strains and serious gastroduodenal disease entities in Korea may be due to the similar capacity for proinflammatory cytokine gene expression and apoptosis caused by infection with each of the H. pylori strains.

Antigens, Bacterial↗

Helicobacter pylori water-soluble surface proteins activate human neutrophils and up-regulate expression of CXC chemokines.

To elucidate the mechanisms of the persistent neutrophil recruitment in H. pylori-infected gastric mucosa, we evaluated the activation of human neutrophils and CXC chemokine expression in neutrophils by H. pylori water-soluble surface proteins. H. pylori water extract (HPWE) was prepared from a supernatant of the H. pylori suspension in distilled water. After neutrophils were stimulated with HPWE, the mobilization of intracellular free calcium, the expression of lymphocyte function-associated antigen-1beta, and the secretion of myeloperoxidase (MPO) were enhanced in the neutrophils. In H. pylori-infected gastric mucosa, transendothelial and transepithelial migration of neutrophils were observed by electron microscopy and mucosal MPO levels were elevated. Up-regulation of the expression of interleukin-8 (IL-8) and growth-related oncogenes (GROs; GROalpha, GRObeta and GROgamma) mRNA and protein in neutrophils by HPWE was demonstrated by quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. In conclusion, H. pylori-induced neutrophil recruitment may be mediated by CXC chemokines which are expressed by neutrophils activated by H. pylori water-soluble surface proteins.

Chemokines, CXC↗

Long-term effects of Helicobacter pylori eradication on intestinal metaplasia in patients with duodenal and benign gastric ulcers.

This study was conducted to investigate whether or not the eradication of H. pylori could lead to the regression of intestinal metaplasia (IM) in patients with either duodenal ulcer (DU) or benign gastric ulcer (BGU). The initial antral IM grade was 0.21 in the 72 patients of the H. pylori-eradicated DU group, this decreased to 0.17, 0.14, 0.13, and 0.09 after periods of four weeks, one year, two years, and four years, respectively, but without statistical significance. In the corpus of the DU group, where IM grade was low (0.02), there was no detectable change in IM. The initial antral IM grade of 0.69 in the 41 patients of the H. pylori-eradicated BGU group decreased substantially to 0.61, 0.44, and 0.39 after periods of four weeks and one and two years, respectively, but again without statistical significance. The initial corporal IM grade of the BGU group of 0.27 decreased to 0.20, 0.15, and 0.06 after periods of four weeks and one and two years, again without statistical significance. In contrast, the IM grades of the noneradicated DU group (N = 20) and the BGU group (N = 16) showed nearly no change in the antrum and corpus. Gastritis grades of antrum and corpus in the H. pylori-eradicated DU or BGU group significantly decreased with respect to time (P = 0.0001), but there were no significant changes in the corresponding noneradicated groups. Although there was no statistical significance, IM decreased in the antrum and corpus of the stomach with BGU and in antrum of those with DU over a two to four-year period after H. pylori eradication, suggesting the possible reversibility of IM.

Adolescent↗

Upregulated cyclooxygenase-2 inhibits apoptosis of human gastric epithelial cells infected with Helicobacter pylori.

Helicobacter pylori induces apoptosis and alters the proliferation of gastric mucosal epithelial cells. Cyclooxygenase-2 (COX-2), the inducible form of prostaglandin (PG) synthesis, is known to cause alteration in epithelial cell growth. The goal of this study was to determine whether COX-2 gene expression by H. pylori infection could influence gastric epithelial cell apoptosis. Expression of COX-2 mRNA and proteins was up-regulated in Hs746T gastric epithelial cell lines infected with H. pylori, when assessed by quantitative RT-PCR and western blot. Inhibition of COX-2 expression using NS-398, a specific COX-2 inhibitor, showed a significant increase of gastric epithelial cell apoptosis and caspase-3 activation in Hs746T cells infected with H. pylori. Moreover, the effect of NS-398 on H. pylori-induced apoptosis was reversed by the addition of PGE2. These results suggest that up-regulated COX-2 expression by H. pylori infection can inhibit apoptosis of gastric epithelial cells.

Apoptosis↗