• Journal of Digestive Cancer Research
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• v.10 no.1
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• pp.9-15
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• 2022

Proton pump inhibitors (PPIs), a potent gastric acid inhibitor, are widely used in gastric acid-related diseases such as gastroesophageal reflux disease and peptic ulcer, and are known as the most frequently used drugs worldwide. However, as the frequency of use increases, the number of cases of long-term PPI therapy without clear indications is increasing. Recently, there have been concerns about the risk of gastric cancer in patients with long-term PPI users. Potential mechanisms for the association between PPI and gastric cancer include enterochromaffin-like cell proliferation due to hypergastrinemia caused by gastric acid suppression, progression of atrophic gastritis, and corpus-predominant type through interaction with Helicobacter pylori (H. pylori) infection. Several epidemiologic studies showed controversial results on the issue, and it is difficult to prove a causal relationship between PPI and gastric cancer. Nevertheless, long-term PPI should be administered cautiously based on individual risk-benefit profile, specifically among those with history of H. pylori infection, in high-risk region of gastric cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1315-1319
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• 2015

The fact that long-term use of proton pump inhibitors (PPIs) aggravates corpus atrophic gastritis in patients with Helicobacter pylori infection has been proven clinically and experimentally. Corpus atrophic gastritis is a known risk factor for gastric cancer. Therefore, gastric neoplasia might be associated with the long-term use of PPIs. One of the causes of worsening corpus atrophic gastritis, leading to the development of adenocarcinoma, might be bacterial overgrowth under conditions of hypochlorhydria. The production of potentially carcinogenic N-nitrosocompounds by nitrosating organisms under conditions of hypochlorhydria might be associated with carcinogenesis. Interactions between bile acids, pH, and H. pylori might also contribute to carcinogenicity, especially in patients with gastro-esophageal reflux disease (GERD). The concentration of soluble bile acids, which have bactericidal or chemorepellent properties toward H. pylori, in gastric contents is considerably higher in patients undergoing continuous PPI therapy than in healthy individuals with normal acid production. Under these circumstances, H. pylori might colonize the stomach body rather than the pyloric antrum. Hypergastrinemia induced by PPI administration might promote the development of gastric cancer. Because the main cause of corpus atrophic gastritis is H. pylori infection, and not PPI administration, H. pylori infection should be eradicated before starting long-term PPI therapy.

• Journal of Yeungnam Medical Science
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• v.30 no.2
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• pp.141-144
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• 2013

Hyperplastic gastric polyps (HPPs) are the most common type of gastric polyps. They are assumed to be caused by chronic inflammation and regenerative proliferation, although this has not been clearly investigated yet. Many studies suggested the development of fundic gland polyps and carcinoid during long-term proton pump inhibitor (PPI) therapy, but the relationship between PPIs and HPPs is still unclear. We encountered a patient who showed aggravation of HPPs after long-term use of PPIs. A 58-year-old male patient with liver cirrhosis visited our hospital because of hematemesis. We started PPI medication after confirming esophageal variceal bleeding and duodenal ulcer with blood clot in its base via emergency endoscopy. He took PPIs for three years because of an intractable duodenal ulcer. There was a marked increase in the size of the pre-existing polyps and in the development of new polyps. We presumed that the PPIs caused the aggravation of the HPPs, so we stopped their administration. After five months, the HPPs shrank and the polyps were partially degraded. More prospective studies are needed to investigate the relationship between HPPs and PPIs.

• Korean Journal of Bronchoesophagology
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• v.16 no.2
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• pp.97-104
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• 2010

Gastroesophageal reflux disease (GERD) is a common disorder caused by the reflux of gastric contents into the esophagus. According to the recent classification, GERD can elicit esophageal and extraesophageal syndromes. Laryngopharyngeal reflux (LPR) is defined as laryngeal symptoms with laryngeal inflammation caused by the acid reflux. The prevalence of GERD and LPR is increasing during the past decades in Korea and management of GERD and LPR is a challenging issue in clinical practice. Proton pump inhibitor is the most effective drug in the treatment of GERD. Most patients with LPR are given a 2-month trial of a proton pump inhibitor (PPI), however, there is still little evidence on the diagnosis or the treatment of LPR. During the last years concern have been raised regarding the risk of averse events related to long-term use of PPI. We review the recent update on medical treatment of GERD/LPR.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.1
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• pp.44-49
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• 2018

High-strength plastic water supply pipe evaluation method was evaluated in this study. Up to date, high strength water supply pipes that we install are mostly ductile cast iron pipes. Sometimes, a few PVC pipes are installed. Metal pipes have rust problem on the surface, causing serious damage to metal pipes and reducing the expected life span of water piping system. Nowadays, depending on technology development, some companies have improved properties of general PVC pipe performance with remarkable properties that exceed KS and ASTM standard. Here, we suggest a new method of performance evaluation for high-strength water plastic pipes.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.sup1
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• pp.55-71
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• 2008

Gastroesophageal reflux (GER) defined as passage of gastric contents into the esophagus without symptoms is a common physiologic gastrointestinal problem in infants, children and even in adults. But gastroesophageal reflux disease (GERD) defined as symptoms or complications of GER is a disease entity to find out the reason and treat. After the era of 1970 we have been studying about GERD with the development of diagnostic and therapeutic methods. I already introduced the nature and the fundamental knowledge of GERD in the opening symposium of KSPGHAN in 1998. Now, I will introduce the guidelines for evaluation and treatment of GERD which was recommended by the North American Society for Pediatric Gastroenterology and Nutrition and American Pediatric Association which was published in 2001. And I will introduce progressing subjects and the forecoming issues to be solved in near future. Those are as followings. Does GERD cause otolaryngologic symptoms such as chronic sinusitis and chronic otitis? Is GERD inherited? Can we find out the child who will become GERD in adult life and the way to reduce the incidence of Barrett's esophagus and esophageal cancer? Is long term PPI therapy safe in children?

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.135-150
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• 2010

This paper focuses on finding out which covenants are different among the concession agreements of Korean BTO projects and how these influenced IRR(Internal Rate of Return). That is, to figure out the political and economical determinants of IRR by analyzing the concession agreements which are the basic contract of implementing projects. As IRR is an index of profitability, so spread is an indicator of risk to collect debts. That's the reason why the analysis of spread is included. For the empirical analysis, the data of concession agreements for 75 projects and financial models are used. These 75 concession agreements are contracted from 1995 to 2008. The dependent variables are after tax nominal IRR and the spread of long term interest rates of 75 BTO projects. The independent variables are project's proceeding factors, the feasibility variables, the variables related to financial character and the variables related to covenants or the government's policy. The analysis shows that IRR has been influenced by the equity level of financial investors, the national government managed projects, the projects with minimum revenue guarantee (MRG), etc. And the equity level of financial investors, the national government managed projects and the implementation of supplementary project have an effect on spread also.