Acciones metodológicas para implementar la estrategia curricular de Inglés con fines profesionales en Medicina / Methodological actions to implement the English language curricular strategy in English for specific purposes in medicine

Fundamento: la finalidad de la estrategia curricular Dominio del Idioma Inglés, propuesta por la subcomisión de estrategias curriculares de la Universidad de Ciencias Médicas de la Habana desde el 2009, es la competitividad idiomática de los profesionales de la salud. Objetivo: diseñar acciones metodológicas para la implementación de la estrategia curricular Dominio del Idioma Inglés en la carrera de Medicina de la Filial Universitaria Municipal de Santo Domingo. Métodos: se realizó una investigación de desarrollo con enfoque mixto entre enero de 2011 y diciembre de 2013; se utilizaron métodos teóricos: análisis-síntesis e inducción-deducción y empíricos: análisis documental de la Resolución 210/2007, planes de trabajo metodológico y actas en los diferentes niveles organizativos, modelo del profesional y planes de clase; y la encuesta en forma de entrevista a directivos, y de cuestionario a docentes para identificar las principales insuficiencias en la preparación idiomática y metodológica. Resultados: se constató que las principales insuficiencias están relacionadas con la dirección y ejecución del trabajo metodológico interdisciplinar y con el pobre desarrollo de habilidades para la gestión de la información médica en idioma inglés, por lo que se diseñaron acciones metodológicas para lograr una mayor objetividad en la implementación interdisciplinar de esta estrategia que tribute al actual modelo del profesional de la salud. Conclusiones: las acciones fueron valoradas como pertinentes por criterios de especialistas, porque contribuyeron a transformar progresivamente la realización del trabajo metodológico para desarrollar una competencia idiomática interdisciplinar y profesional como garantía de un desempeño competente en contextos de habla inglesa.

Background: the purpose of the curricular strategy of the English Language command, proposed by the subcommittee of curricular strategies of Havana University of Medical Sciences since 2009 is the idiomatic competence of health professionals. Objective: to design methodological actions for the implementation of the curricular strategy of the English Language command in the Medicine career of Santo Domingo's Municipality Health University Site. Methods: it was carried out a development investigation with a combined approach from January 2011 to December 2013; theoretical methods were used: analysis-synthesis and induction-deduction and empiric ones: documental analysis of the 210/2007 Regulation from the Ministry of Higher Education , methodological plans and meeting records at different organizational levels, model of the professional and lesson plans; and the survey in interview form was applied to administrative leaders and a questionnaire was applied to the professors to identify the main inadequacies in the idiomatic and methodological preparation. Results: it was verified that the main inadequacies are related with the management and execution of the interdisciplinary methodological work and with the poor development of abilities for the medical information management in the English language, that's why methodological actions were designed to achieve a bigger objectivity in the interdisciplinary implementation of this strategy that contributes with the current model of health professionals. Conclusions: the actions were valued as pertinent by the specialists' criteria, because they contributed to transform the work with the methodological activity progressively to develop an interdisciplinary and professional idiomatic competence as guarantee of a competent performance in English-speaking contexts.

Fitoplancton del río Tehuantepec, Oaxaca, México y algunas relaciones biogeográficas / Phytoplankton from Tehuantepec River, Oaxaca, Mexico and some biogeographical relationships

Phytoplankton species collected from the limnetic to euryhaline sections of Tehuantepec River were identified, classified and compared with regional information from Mexico and South America. We collected 15 samples every three months from July 1997 through August 1998 with a 20 microm net and a Van Dorn bottle. Indicator values and a code checklist are included. A total of 58 families, 121 genera, 273 species, one subspecies, 75 varieties, 13 forms and one morphotype were identified in the taxa Bacillariophyta (42.0 %), Chlorophyta (29.0 %), Cyanoprocaryota (18.0 %), Euglenophyta (5.0 %), Dinophyta (3.0 %), Cryptophyta (2.0 %) and Chrysophyta (1.0 %). The predominant families were Scenedesmaceae (24 species), Oocystaceae (22), Bacillariophyceae (21), Chaetocerotaceae (15) and Euglenaceae (14). Five families, eight genera, 72 species, 45 varieties and eight forms are first records for Mexico. The species Chroococcus turgidus, Microcystis flosaquae and Pseudanabaena limnetica (which produce massive blooms or red tides) are important in this river of moderate water quality.

El fitoplancton recolectado en el río Tehuantepec con características limnéticas a eurihalinas se determinó, clasificó y comparó con información regional de México y Suramérica. Se incluyen valores indicadores y un código del listado florístico para facilitar el manejo de estas algas. Se determinó un total de 58 familias, 121 géneros, 273 especies, una subespecie, 75 variedades, 13 formas y un morfotipo, pertenecientes a las divisiones Bacillariophyta (42.0 %), Chlorophyta (29.0 %), Cyanoprocaryota (18.0 %), Euglenophyta (5.0 %), Dinophyta (3.0 %), Cryptophyta (2.0 %) y Chrysophyta (1.0 %). Las familias mejor representadas fueron Scenedesmaceae (24 especies), Oocystaceae (22), Bacillariophyceae (21), Chaetocerotaceae (15) y Euglenaceae (14). Se establecen nuevos registros para México: cinco familias, ocho géneros, 72 especies, 45 variedades y ocho formas. En este río, que presenta una moderada calidad del agua, sobresalieron las especies Chroococcus turgidus, Microcystis flosaquae y Pseudanabaena limnetica (como productoras de mareas rojas).

The Relationship between Ineffective Esophageal Motility and Gastro-esophageal Reflux Disease / 대한소화기학회지

BACKGROUND/AIMS: Ineffective esophageal motility (IEM) is a distinct manometric entity characterized by a hypocontractile esophagus. Recently, IEM replaced the nonspecific esophageal motility disorder (NEMD), and its associations with gastro-esophageal reflux disease (GERD) and respiratory symptoms are well known. We evaluated the relationship of IEM with GERD, and the diagnostic value of IEM for GERD. METHODS: We retrospectively analyzed recent 3-year (Jan. 1998-Sep. 2002) datas of esophageal manometry, acid perfusion test and simultaneous 24 hr-ambulatory pH-metry with manometry studies in 270 consecutive patients with esophageal and/or GERD symptoms. The prevalence of IEM in GERD group and non-GERD group, and the variables of pH-metry and manometry among esophageal motility disorders were compared. In addition, the sensitivity, specificity, positive predictive value, negative predictive value of IEM, esophageal symptom, and acid perfusion test for GERD were calculated. RESULTS: There was no significant difference in IEM prevalence rate between GERD group and non-GERD group. In addition, there was no significant difference in GERD prevalence rate and esophageal acid clearance in variety of motility disorder groups. Total percent time of pH <4 in IEM group did not show any difference when compared with other groups except in the achalasia group. In regard of diagnostic value to detect GERD, all positive results showed high specificity (97%) in IEM with esophageal symptom and positive acid perfusion test. CONCLUSIONS: The diagnosis of IEM using esophageal manometry in patients with various esophageal symptoms does not strongly suggest on association with GERD. However, IEM with concomitant esophageal symptoms and positive acid perfusion test has diagnostic values for GERD.

Clinical Effectiveness of Transcatheter Arterial Embolization for Acute Upper and Lower Non-variceal Gastrointestinal Bleeding / 대한소화기학회지

BACKGROUND/AIMS: Although the initial rate of hemostasis achieved by endoscopic treatment for acute non-variceal gastrointestinal bleeding (NVGIB) is high, recurrent or persistent bleeding occurs in 10% to 25% of the patients. The aim of this study was to assess the efficacy and safety of transcatheter arterial embolization (TAE) in patients with acute upper and lower NVGIB who could not be managed by endoscopic treatment. METHODS: A retrospective analysis of the clinical data was done in 43 patients (M/F: 26/17, mean age: 60 years) whom underwent angiography or TAE for acute upper and lower NVGIB between January 1998 and December 2003. Among 43 patients, 18 had upper NVGIB, 19 had lower NVGIB, and 6 had obscure gastrointestinal bleeding. Demographic characteristics and outcome parameters including the rates of hemostasis, in-hospital death, and complications were analyzed. RESULTS: Thirty-four patients underwent TAE while 9 patients underwent angiography. TAE was used as the first line treatment in 17 patients and as the second line treatment in others. Hemostasis was achieved in 29 of 34 patients (85.3%) by TAE. According to the site of bleeding, hemostasis was achieved in 14 of 17 patients (82.4%) with upper NVGIB and in 15 of 17 patients (88.2%) with lower NVGIB. There was no significant angiography or TAE-related complications such as bowel ischemia or infarction except a hematoma on the angiography site in one patient. CONCLUSIONS: TAE is effective and safe in patients with acute upper or lower NVGIB who cannot be managed by endoscopic treatment.

Grading of Histology, Expression of Apoptosis and Cell Proliferation in Gastric Mucosa Adjacent to Gastric Adenoma or Adenocarcinoma / 대한소화기학회지

BACKGROUND/AIMS: Helicobacter pylori (H. pylori) infection can lead to gastric adenoma and carcinoma through atrophic gastritis and intestinal metaplasia. Imbalance between apoptosis and proliferation may play a role in gastric carcinogenesis. We tried to investigate H. pylori infection rate, grade of gastritis, environmental risk factors, expression rate of apoptosis and cell proliferation in mucosa adjacent to tumor, and we also tried to find significant factors associated with gastric carcinogenesis. METHODS: Endoscopically diagnosed twenty cases of intestinal type gastric carcinoma, 20 cases of gastric adenoma, and 40 cases of control (normal or gastritis) were enrolled. H. pylori infection rate, histologic grading, apoptosis and immunohistochemical stain (Ki-67 and p53) to check mucosal proliferation were done in endoscopically biopsied tissues at antrum and body at least 2 cm apart from adenoma or carcinoma. RESULTS: In three groups, H. pylori infection rates were not significantly different. In the multivariate analysis, only atrophy of gland was a significant risk factor for adenoma compared to control group (OR 3.7). Intestinal metaplasia in antrum and alcohol drinking were significant risk factors for carcinoma compared to control group (OR 4.4 and 4.9 respectively). Expressions of apoptosis, Ki-67 and p53 were not significantly different in three groups. CONCLUSIONS: Intestinal metaplasia in antrum and alcohol drinking are significant risk factors for gastric carcinoma. Degree of mucosal proliferation and apoptosis in gastric mucosa adjacent to tumor are not significantly different in three groups.

The Current Status of Ulcerative Colitis-associated Colorectal Cancer in Korea: A KASID Study / 대한소화기학회지

BACKGROUND/AIMS: The number of patients with ulcerative colitis has steadily increased since the mid-1980s. As the risk of colon cancer increases with duration and extents, colitic cancers are expected to increase in number in Korea. We surveyed the current status of colitic cancers and provided the perspectives in Korea. METHODS: Korean Association for the Study of Intestinal Diseases (KASID) collected and descriptively analyzed a total of eleven cases of colitic cancers occurred between 1993 and 2003. RESULTS: The mean age at the diagnosis of colitic cancer was 49.3 years, and the mean duration of ulcerative colitis was 12.5 years. Of the diagnosed cases, 91% was associated with pancolitis, 28% had right colon cancers and 18.2% had multiple tumors. Colitic cancers diagnosed at Dukes' stage D were 36.3%. Stages at diagnosis were lower in patients with good compliance. Up to 2003, cumulative incidence ratio of colitic cancer to ulcerative colitis was estimated to be 0.5%, which was much less than the overall prevalence of 3.7% in the Western countries. This incidence was also less than the expected cumulative incidence ratio of 0.9%, which was estimated by adopting the average results of meta-analysis in the Western world. CONCLUSIONS: As the incidence of ulcerative colitis has not reached a plateau, and as the diagnosis of colitic caners are delayed in Korea, the cumulative incidence of colitic cancers might have appeared to be low. Geographic and racial factors, and the effect of preventive measures might have contributed to the lower incidence which remains to be proven. Since colitic cancers are expected to increase steeply in the near future in Korea, the importance of surveillance and prevention cannot be over-emphasized.

Prognostic Factors and Survival according to the Okuda Stage in Patients with Hepatocellular Carcinoma / 대한소화기학회지

BACKGROUND/AIMS: There are several staging systems to decide the stage of hepatocellular carcinoma (HCC), but yet incomplete. Okuda stage which includes both tumor characteristics and liver function is widely used. The aims of this study were to assess the usefulness of known prognostic factors and Okuda staging system in 237 cases of HCC. METHODS: A retrospective analysis of 237 cases of HCC diagnosed from 2000 to 2002 was performed. We analyzed prognostic factors such as age, sex, liver cirrhosis, Child-Pugh classification, tumor size, albumin, bilirubin, alpha-FP, ascites, encephalopathy and Okuda stage. Prognostic analysis was performed for single variables and estimating survival distributions were analyzed by the Kaplan-Meier method, statistically compared by the log-rank test. RESULTS: Patients had a mean age of 57.5 years and were predominantly men (79.7%). Liver cirrhosis were noticed in 214 cases (90.3%). The overall median survival period was 25.7 months. The median survival period was correlated to bilirubin, ascites, alpha-FP, tumor size, and Child-Pugh classification, but not to age, sex, and pattern of viral infection. The median survival period of the Okuda stage I, II and III cases was 35.8, 11.9 and 8.5 months (p<0.001). CONCLUSIONS: The median survival period of patients with HCC is significantly correlated to Okuda staging system, and survival period has improved than the initial data when the Okuda staging system was published in 1985. However, in order to discriminate early staged HCC more accurately, other prognostic factors such as alpha-FP and tumor morphology should be included in future staging system for HCC.

Expression of Hedgehog Proteins in Periampullary Cancer / 대한소화기학회지

BACKGROUND/AIMS: Hedgehog protein is an essential molecule for gastrointestinal tract development, and disruption of hedgehog signaling pathway is linked to some gastrointestinal tumorigenesis. Here, we performed hedgehog immunostaining in periampullary cancer to evaluate the differences according to the location type of cancer and the differentiation of adenocarcinoma. METHODS: We retrieved surgical specimens from 43 periampullary cancer patients (15 ampulla of Vater cancer, 12 distal common bile duct cancer, 13 pancreatic head cancer, and 3 combined ampulla of Vater/bile duct cancer). Immunohistochemical stain was performed in both normal and cancerous tissue portions of each case using Sonic hedgehog (H-160) rabbit polyclonal antibody. Immunohistochemical stain results were grouped into three groups according to the percentage of positive cytoplasmic stain in tumor volume (unstained: 50%). RESULTS: All of the normal tissue revealed negative immunohistochemical stain while cancerous tissue revealed positivity in 95.3% (41/43 cases). Strongly stained cases were more frequently seen in ampulla of Vater cancers (13/15) and in combined ampulla of Vater/bile duct cancers (3/3) than in distal common bile duct cancers (4/12) and in pancreatic head cancers (3/13) (p=0.002). In addition, strongly stained cases were more frequently seen in well-differentiated adenocarcinoma than the others (p<0.001). CONCLUSIONS: Most of the periampullary cancers show hedgehog protein expression. In addition, hedgehog protein immunostainings shows stronger expression in ampulla of Vater cancers and in well-differentiated adenocarcinoma.

A Case of Refractory Pediatric Crohn's Disease with a Successful Treatment by Infliximab Therapy / 대한소화기학회지

Crohn's disease is a chronic inflammatory bowel disease which affects mainly children and young adults, and its cause remains unknown so far. Infliximab, a monoclonal antibody to the pivotal cytokine tumor necrosis factor-alpha, has been approved as a drug for both induction and maintenance therapy for moderately to severely active, or fistula-complicated Crohn's disease. The authors report a 12-year-old male patient diagnosed as Crohn's disease complicated with a perianal fistula, which was refractory to the conventional therapy. After the 0, 2, and 6 week scheduled intravenous infusion of infliximab, the patient reached to clinical remission in both subjective symptoms and objective manifestations. For children or young adults who develop Crohn's disease in a refractory course, infliximab may serve as a drug which leads to a clinical improvement or even to an extent of remission.

A Case of Retroperitoneal Schwannoma of the Vagus Nerve / 대한소화기학회지

Schwannomas are benign nerve sheath tumors that originate from any anatomical site. Most schwannomas occur in the head, neck or limbs, but rarely occur in the retroperitoneal space. Furthermore, the schwannoma originating from the vagus nerve of retroperitoneal space is much rare. We experienced a case of retroperitoneal schwannoma of the vagus nerve. A 34-year-old male was refered to our hospital for the evaluation of abdominal mass on ultrasonography. Endoscopic examination revealed submucosal tumor-like lesion on high body of the stomach. Computed tomography (CT) revealed that the stomach was compressed by a solid tumor in the retroperitoneum. On exploratory laparotomy, this mass turned out to be a baseball sized mass in the retroperitoneal space. The mass was excised in an encapsulated state. Histological examination with immunohistochemical stains revealed a schwannoma of the vagus nerve.

A Common Bile Duct Web in Association with Common Bile Duct Stone / 대한소화기학회지

Webs are diagnosed by their characteristic appearance on imaging studies, typically appearing as thin, radiolucent rings with or without dilatation of the organ proximal to it. Like in other organs, the etiology of webs in the common bile duct is controversial. Some webs are thought to be congenital, whereas others occur in the presence of chronic inflammation, suggesting a pathogenic relationship. We report a case of a common bile duct septum in association with numerous large black pigment stones in a 62-year-old woman. The patient was treated by cholecystectomy with T-tube insertion.

Hepatocellular Carcinoma in Korea: Introduction and Overview / 대한소화기학회지

Hepatocellular carcinoma (HCC) is a highly malignant, generally fatal neoplasm arising from hepatocytes. HCC accounts for over 80% of all primary liver cancers which ranks fourth among the organ-specific causes of cancer-related deaths worldwide. HCC is particularly prevalent in Korea where the age standardized incidence rate is 46.5 per 100,000 population. Infection with hepatitis B virus (HBV) or hepatitis C virus (HCV) or presence of liver cirrhosis are important risk factors for HCC development globally. Infection with HBV is the most important risk for HCC in Asia except Japan. The high incidence rate of HCC in Korea is thought to be related to the high carrier rate (5-6%) of HBV, which is currently being fought via a nationwide vaccination program. Although progress has been made in the management of HCC including chemoembolization and local ablation therapy, there has been little overall reduction in HCC mortality during the past 20 years. Recently, five year survival rate of primary liver cancer is 9.6% in Korea. Such poor prognosis of HCC results from the late detection of cancer, an aggressive tumor biology and underlying chronic liver diseases. Only a limited proportion of patients are candidates for potentially curative forms of treatment. Therefore efforts should be directed toward an effective surveillance program. The early detection of HCC is the important approach in reducing HCC mortality in the short term. Because almost eighty percent of HCC is diagnosed in late stage, we launched a nationwide surveillance program to screen high risk groups (HBV or HCV carriers or liver cirrhosis, over 40 years old) and formulated the Korean practice guideline for the diagnosis and treatment of HCC with special emphasis on advanced stage of HCC.

Pathology of Hepatocellular Carcinoma: Recent Update / 대한소화기학회지

In recent years, growing number of literatures have supported the concept that large nodules usually found in cirrhotic livers represent premalignant lesions in the setting of chronic liver disease. With the use of advanced imaging techniques, nodules suspicious for malignancy have often been identified and resected. While some resected lesions were found to be small hepatocellular carcinomas (HCCs), others were not. Some of these non-malignant nodules were devoid of atypia, some had architectural or cytological atypia insufficient for a diagnosis of HCC though they are suggestive of a premalignant state, while others contained microscopic subnodules of HCC. In follow-up studies and series of explants from liver transplant centers, the occasional finding of microscopic foci of HCC in the nodules was confirmed and significant associations with HCC elsewhere in the same liver were established. Such findings suggested that these nodular lesions, which are referred as "dysplastic nodules" (or adenomatous hyerplasia), are probably a frequent pathway in human hepatocarcinogenesis. We discuss the pathological characteristics of dysplastic nodules and small HCCs.

Imaging Diagnosis of Hepatocellular Carcinoma / 대한소화기학회지

In patients with chronic liver disease, hepatocelluar carcinomas are developed from regenerative nodule via dysplastic nodule and early hepatocellular carcinoma to advanced hepatocellular carcinoma during multistep hepatocarcinogenesis. In this article, imaging findings of various imaging modalities are described pertaining to the above mentioned hepatocellular nodules occurring in the cirrhotic liver, correlating with pathologic findings.

Surgical Treatment of Hepatocellular Carcinoma / 대한소화기학회지

Due to recent rapid advances in imaging modalities, there has been a marked increase in the early diagnosis of hepatocellular carcinoma (HCC). Also, the emergence of effective local treatment methods has lead to the necessity for a wider selection of therapeutic modalities depending on the individual characteristics of each patient, such as tumor factors and hepatic factors, rather than a single uniform approach. At present, accurate preoperative liver function evaluation is available, and in addition, increased knowledge of the liver anatomy through liver transplantation, and advances in postoperative patient care has subsequently decreased the morbidity and mortality rates significantly after surgery. Such newly developed techniques and acquired knowledge has allowed the surgical option to expand from the classical hepatic lobectomy to systematic subsegmentectomy. Not only for early HCC, but also for intermediate HCC and advanced HCC, hepatectomy has shown the best results in each stage of disease with regard to treatment goals. It is therefore thought that hepatectomy should always be considered as the main treatment method in the multimodality treatment of HCC, as long as the liver function reserve permits, to enhance the quality of life, increase survival, and to cure disease. The authors present here a summary of the role of surgical approaches in HCC with respect to recent increases in the detection of early stage disease, new therapeutic modalities, and a new staging system for HCC.

Radiological Intervention of Hepatocellular Carcinoma / 대한소화기학회지

In spite of the nice screening program using the state-of-the-art imaging modalities, most patients with hepatocellular carcinoma (HCC) are not eligible for curative resection due to poor hepatic functional reserve and multiplicity of the tumors. Therefore they greatly rely on percutaneous interventional procedures. Among these, transcatheter arterial chemoembolization and local ablation therapies including ethanol injection therapy or radiofrequency (RF) thermal ablation have gained wider acceptance for the local treatment of unresectable HCC with growing evidence of survival gain. Although we need more prospective randomized trials to determine the definite role of these interventional therapies, the current consensus is that they are safe and effective for the local control of small HCC and have a potential to replace definitive surgical options. In this review, the basic principles and published clinical results including long-term survival rates and complications are reviewed. The benefits and limitations of each therapy are also discussed.

Experimental Treatment of Hepatocellular Carcinoma / 대한소화기학회지

Hepatocellular carcinoma (HCC) is one of the most common malignancies world wide. Several experimental treatments have been tested against HCC. Those are chemotherapy, high dose proton beam radiotherapy, external beam radiotherapy, cyberknife, antibody-directed therapy and immunotherapy. Neither single nor combination therapy have demonstrated any clear reproducible benefit in terms of overall survival. Tamoxifen and antiandrogen therapy were not effective in prolonging survival when tested in randomized controlled trial. The modern radiation therapy concept such as intensity-modulated, image-guided, and stereotactic body radiation therapy may show promising effects on HCC. The increasing promise of targeted drug therapy in cancer needs to be particularly pursued in the treatment of HCC, in which cytotoxic agents are not usually effective. Other approaches include hormonal manipulation, immunotherapy, and specific inhibition of angiogenesis or growth factors. These issues stress the need for basic research in carcinogenesis in general and HCC in particular.

The Inhibitory Effect of Curcumin on the Growth of Human Colon Cancer Cells (HT-29, WiDr) in vitro / 대한소화기학회지

BACKGROUND/AIMS: The effects of curcumin on the growth of human colon cancer cell lines, HT-29 and WiDr cells were examined and the effects of 5-fluorouracil (5-FU) were also studied. METHODS: The growth of HT-29 and WiDr cells were examined by counting cell number on two and four days treatment with 1-40 micrometer of curcumin, and 0.1 microgram/mL, 0.3 microgram/mL of 5-FU. The reversibility of curcumin was examined on one day to seven days treatment with 10 micrometer curcumin after seeding to 2 10(4) cells/well. To examine the inhibitory effects of curcumin, cell cycle analysis was done on the HT-29 cells after four days treatment with 20 micrometer curcumin. RESULTS: Curcumin inhibited the growth of HT-29 and WiDr cells in a dose-dependent fashion. The growth rate of the group in which curcumin was removed by media change 24 hours after the treatment of curcumin was not different from that of control group. Curcumin combined with 5-FU markedly inhibited the growth of HT-29 and WiDr cells compared to curcumin or 5-FU alone. After four days treatment of HT-29 cells with 20 micrometer curcumin, the fraction of cells in G2-M phase was 35.3% in curcumin group, much higher than 13.8% of the control group. CONCLUSIONS: Curcumin significantly inhibited the growth of HT-29 and WiDr cells in a dose- dependent, reversible fashion.

Frequent Epigenetic Inactivation of XAF1 by Promotor Hypermethylation in Human Colon Cancers / 대한소화기학회지

BACKGROUND/AIMS: X-linked inhibitor of apoptosis (XIAP) is the most potent member of the IAP family that exerts antiapoptotic effects. Recently, XIAP-associated factor 1 (XAF1) and two mitochondrial proteins, Smac/DIABLO and HtrA2, have been identified to negatively regulate the caspase-inhibiting activity of XIAP. We explored the candidacy of XAF1, Smac/DIABLO and HtrA2 as a tumor suppressor in colonic carcinogenesis. METHODS: Expression and mutation status of the genes in 10 colorectal carcinoma cell lines and 40 primary tumors were examined by quantitative PCR analysis. RESULTS: XAF1 transcript was not expressed or present at extremely low levels in 60% (6/10) of cancer cell lines whereas Smac/DIABLO and HtrA2 are normally expressed in all cell lines examined. Tumor-specific loss or reduction of XAF1 was also found in 35% (14/40) of matched tissue sets obtained from the same patients. XAF1 transcript was reactivated in all the low expressor cell lines by treatment with the demethylating agent 5-aza-2'-deoxycytidine. Moreover, bisulfite DNA sequencing analysis for 34 CpG sites in the promoter region revealed a strong association between hypermethylation and gene silencing. Restoration of XAF1 expression resulted in enhanced apoptotic response to etoposide and 5-flurouracil, whereas knockdown of XAF1 expression by siRNA transfection significantly inhibited chemotherapeutic drug-induced apoptosis. CONCLUSIONS: XAF1 undergoes epigenetic gene silencing in a considerable proportion of human colon cancers by aberrant promoter hypermethylation, suggesting that XAF1 inactivation might be implicated in colonic tumorigenesis.

The Detection of Antigenic Protein of HCV in Gastric Mucosa / 대한소화기학회지

BACKGROUND/AIMS: As a preliminary study to test the possibility of oral transmission of hepatitis C virus (HCV), many investigations in order to detect the extrahepatic localization of HCV have been performed. In this study, we examined the presence of HCV viral proteins in gastric mucosa. METHODS: Immunohistochemical staining to NS3 protein were done to detect the HCV virus in gastric mucosa. The results were compared with NS5a protein staining to confirm the NS3 protein staining. RESULTS: Total of 164 patient were included. 58 patients with anti-HCV (+) were designated to case group and 70 with anti-HCV (-) to control group. 36 were excluded in this study due to concomittent illness. Anti-HCV (+) group showed 50.0% (29/58) of positivity to NS3 protein staining and anti-HCV (-) group showed 12.6% (9/70) of positivity (p<0.001). Immunohistochemical staining to NS5a protein were done to validate the result of NS3 (+) staining in the anti-HCV (+) group (n=58). NS5a (+) staining were observed in 58.6% (34/58). The results of NS5a staining were consistent with that of NS3 in 70.7%. The reliability coefficients by Chronbach's Alpha for NS3 and NS5a stain test was 0.59. CONCLUSIONS: HCV can exist in gastric mucosal cell as an extrahepatic presence. In the future, this study may provide some fundamental data for the research of possible oral transmission route of HCV.